I know many gravitate toward Siakam as a comp when looking at a young frontcourt player is mentioned
To be clear, I wasn't comparing Looney to Siakam per se — just using Siakam as a (rather extreme) example of a player in their age 22 season not being anywhere close to a finished product. At the same time, I'm keenly aware that most 22 year-old players don't make anywhere near the leap from age 22-24 that Siakam has.
Siakam also didn't touch a basketball until 5-6 years prior to entering the NBA and was an excellent ballhandler in college for a frontcourt player. He put up 20/12/2 his final year at New Mexico State and named his Conference Player of the Year...….it wasn't like he was raw and unskilled when he entered the league.
As I understand it, having no early background in hoops can be much of negative as a positive with respect to projection, since many "late-bloomers" never gain the critical muscle memory, fundamentals, and/or feel for the game of a guy weaned on hoops. Yes, Siakam was productive as a 21 year old in the WAC against the likes of Utah Valley and Grand Canyon; but that should be looked at through a slightly different lens from what Looney — as an 18 year old starting the season coming off hip surgery, and finishing it with a mask from a broken face — did at UCLA. In any case, Siakam's rookie year numbers (9.6 points / 0.7 assists per 36, .523 true shooting, .143 from three) suggest he was indeed pretty raw and unskilled entering the league. I didn't follow Siakam at age 18-21 very closely, but my general sense is that he was significantly behind Looney (a former point guard) in terms of ball skills, shooting, passing, and hoops IQ at similar ages.
Looney was a Top-15 player coming out of HS (ESPN had him 11th) and he's never taken anywhere near the leaps that Siakam has over the past 5-6 years. These two players are on completely different trajectories.
They are now, because Siakam has taken the leap from age 22 to 24 that the vast majority of players do not. But I don't think anyone without benefit of hindsight can claim that Siakam in his age 22 season was the better player than Looney in his (current) age 22 season. Looney at 22 is the better passer, ballhandler, rebounder, scorer, and defender, with a much more positive impact on the scoreboard than 22 y.o. Siakam. I would definitely allow that 22 y.o. Siakam had more physical upside: though similarly sized (Looney has the slightly better wingspan and standing reach), Siakam seems like the significantly quicker and more explosive athlete, especially after Loon's multiple hip surgeries. Positionally, I think Siakam's quickness allows him to be more of a modern-day 3-4 in the PG/LeBron/Durant mode, where Loon looks destined to be more of a 4 / smallball 5. That's a pretty significant difference.
I'm just saying I wouldn't discount the possibility of Loon — who already shows nice form on his jumper, good court vision and feel for the game, and is by all accounts a hard worker and ultra high character guy — developing into something well beyond where he is now. Given his 40% from three at UCLA (in a smallish sample) and nice-looking shooting form I think it's better than 50-50 that he develops a credible (>33%) NBA three ball; and I think that alone with his current defensive and offensive repertoire makes him a ~$15M player in today's NBA.