I have a really hard time picturing it being anything more than a fringe sport, although I'd love to be proven wrong. The American sports calendar is packed year-round., and there are already several other sports what are wildly popular once every 4 years, like swimming, gymnastics, figure skating, etc. but only a small percentage of people who watch those sports during the Olympics pay attention the other 3 years.
People said the same about MLS back in the mid to late 90s, too. And while they have plenty of lingering problems, average attendance
meaningfully and consistently above 20k / game across nearly 400 games means it's fought its way to the big leagues, and our nomenclature of "big 4 sports leagues" is what's behind the times at this point.
This might be more of a standalone thread in General Sports, but I've spent some time recently looking in depth at fringe pro leagues in the country as part of other commitments I have, and like any business venture there are a few big successes, a lot of failures, and rampant survivorship bias by anyone on the outside looking at it in retrospect. If you look at pro lacrosse leagues, for Box lacrosse the NLL is largely successful and stable but at ~9k/game with 10 teams, after 30 years of operation - but there have also been no fewer than 10 failed attempts at starting one. For Field lacrosse, MLL is barely hanging on, with a lot of team turnover, despite 15+ years of operation, and it follows on several failed attempts themselves. So I don't want to overstate that counterpoint about MLS, because the odds of entrepreneurial success are
always low. And as we all know, the NWSL is the USSF's third attempt at a women's league.
As far as I can tell, the problem isn't the sport, it's that it's a women's league. There are simply no precedents for a successful women's league for a team sport with city-based teams. You're looking instead to individual sports with a traveling tournament model - the WTA, LPGA and things like Beach Volleyball. There are still prevailing attitudes from a surprising share of men who view it as a minor league of sorts, a sideshow, and aren't interested in watching on a regular basis. So, frankly, the NWSL and USWNT aligning themselves with general feminist and LGBTQ movements / groups is a savvy play, because it may be the only way they get to critical mass. That, and any sort of decent streaming or TV access for serendipitous discovery (the inept way in which they've gone about that is its own conversation).
The WNBA is closer than the NWSL to stability, partly because their
attendance figures are fairly stable at around 7-8k / game league-wide. But it also hasn't grown attendance-wise in the last decade (with NY's team
plummeting 75% to last due to a move from MSG to White Plains), and prior to 2010 saw a number of new teams fold. Attendance is "real" in a way that TV ratings might not be (as you point out). But the most popular women's basketball team in the country remains the Connecticut Huskies.
The lesson I take from the WNBA's struggles is actually this: the venue they play in, and the year-to-year stability of that venue, is absolutely crucial in terms of building a fan base. Move around a lot, or be located in some weirdass place, and you're going to fuck yourself. Not for nothing do top men's pro leagues all want to own their own venue - failure to do so means they are the mercy of whimsical landlords who seem to come up with all sorts of fucked up reasons for why they need to either double your rent, deny you your preferred match dates, or turf you out entirely without much notice. Add to that usual mayhem the extra factor of a bunch of old white dudes faced with a possible-successful women's team and the seeming extra propensity of them to be cruel or careless towards them, and it's simply a strategic imperative for NWSL to get good venues. Venues ideally part- or all-owned by the teams, or at very worst with very long-lasting leases with explicit date commitments. I believe if they can take care of that, the other strategic choices they've made will have a real chance of paying off.
The easiest bootstrap to that position, of course, is to be co-owned by an MLS or USL team that will let them use their venue, or at least their practice venue, on a consistent and long-term basis. We could break down the situation team-by-team, but I'm willing to bet the team owners have had this at the very top of their war-room whiteboards for a long time and it's more difficult than I realize for either financial reasons or considerations that I don't fully understand. But it's also true that it's not particularly hard to find venues with capacity of 7-10k. If I can name half a dozen within easy public transport range in the most expensive and densely-packed city in the country, I'm willing to bet it's a pretty solvable problem in most top-30 metro areas.
I honestly don't know the answers, and I really wonder if the fight for equal pay will result in the WNT players making more per game but the league funding being cut or eliminated. In truth, that might not be the worst thing, because I think the only real chance of success at this point in time would be for all of the world's best players to be in a single league, and that may be better placed in Europe than the US.
I disagree with this. We have a huge, staggering advantage conferred on us in terms of talent due almost entirely to Title IX. Two generations in, that gives us not just higher-end talent (more people making up the bell curve = the top handful at the end of the bell curve are that much farther from the median), but also more women who've played and retain an interest in playing, retain an interest in watching, in having their kids watch, etc. That advantage more than makes up for the relative poverty of our pro men's soccer teams (vs Europe). Concentrating talent in a single league would just give a better experience to the existing fans, I don't think it's going to bring in meaningfully more incremental fans (I mean, articulate to yourself the mentality that would swing a fence-sitter who's only mildly interested, to start attending matches - it's a stretch, no?). No, I think what's best for women's soccer is to have (1) tighter partnerships or co-ownership with MLS / USL clubs, (2) venue stability, and (3) some credible degree of digital marketing and TV production.
That third one is key, and nobody's gotten it right yet. The good news there is, there are a ton of second-tier broadcasters that can bring that credible production to life. My sport-of-passion, ultimate, broadcasts through
Stadium, a streaming subscription service. You've got CP's corporate overlords DAZN trying to make sports inroads in the US. It doesn't take a ton of imagination, and it doesn't take ESPN-quality production. But you need to market those rights professionally, and do so to optimize for reach moreso than squeezing every last dollar out of it. Long-term stability is in attendance figures, and digital access is an input to that, not separate / adjacent to that.