As much as we want to attribute it to bad QB and bad OL play, I'd argue that defenses are just ahead of the curve at the moment. Edge rushing has gotten better overall, and teams seem to have developed pretty sophisticated schemes to stunt and delay blitz, and offenses/rules haven't caught up.
Much in the way that the league tightened the rules on defending passes twenty years ago, I wouldn't be surprised if the league is looking for ways to slow down QB pressures. Allowing a little more holding for example.
Defenses are ahead of the curve, after being behind the curve due to rule changes and offensive innovations in prior years. It's one of the cool things about football to me, it's a constant chess match between the offense and defense in terms of scheming and personnel, and rarely is it an even battle.
It took years for defenses to catch up to the chances, but now you see it, particularly with a focus on speed and range of coverage on that end. Linebackers are much smaller now, gone are the Brandon Spikes of the world, the 265lb thumper who stopped the run--the best linebackers are basically the size of strong safeties from 20 years ago. You also don't see the prototypical Wilfork/Ted Washington nose tackle anymore--instead defensive tackles are lighter and more explosive, similar to Aaron Donald. There are also in general, more defensive backs on the field then ever before, which puts a premium on secondary depth. For all the problems the Patriots have, one thing they have successfully done over the last two seasons is get a lot faster on defense.
I do think there is a problem with QB play and QB development that has a number of factors that has led to some truly wretched QB this year:
1. Offenses are now built entirely around QBs. If in the past a QB was responsible for like, 50% of your offense, then having a mediocre QB wasn't a deal-breaker. If that number is now around 70% of your offense, then having a lousy QB really handicaps how teams can move the ball. Conversely, if you are fortunate enough to have an elite QB, it makes a much bigger difference on the outcome of games.
2. The offensive systems are so complex and diverse, many of them rely on QBs with incredible physical tools without as much thought being put into the execution side. If you have a Mahomes or Jalen Hurts, that's awesome, but those guys are freaks. Instead you see a lot of QBs being drafted off of raw physical potential, and that leads to Justin Fields, Zach Wilson, Trey Lance, getting picked very high in the draft and being busts.
3. In a related note, the college game is not producing pro-style QBs at a strong rate. Ultimately, the talent in the NFL is what the colleges are giving it, and there just aren't a lot of pro-level QBs getting developed in college, whether that is too great of a difference between standard college and pro systems, excessive transferring stunting development, strong athletes no longer being able to rely on just athleticism at the pro level, or anything else.
4. Most teams don't want to waste valuable cap space on a veteran back-up QB. I think Joe Flacco would be a lot better than a good number of the back-up QBs we have seen play so far this season, but he isn't coming to camp for a minimum salary, and teams balk at paying that and the result is Tommy DeVito and Jarren Hall.