I don't know how they measure standing reaches now, but everyone's is kind of messed up the last few years compared to how they used to measure, they don't even make sense. Giannis' wasn't even measured officially at the combine, so we're just going off reports, but look at some of the tests just on Davis:
2010 NBA top 100 camp: 6'8 in socks, 7'2 wingspan, 9'0 standing reach.
2012 NBA draft Combine: 6'9.25(6'10.5 in shoes), 7'5.5 wingspan, 9'0 standing reach.
How is that possible? Andre Drummond's seemed extremely off that year too. 6'11.75, with a 7'6.25 wingspan... 9'1.25 standing reach. Huh? The draft combine is measuring differently than they used to, and differently than other camps are for sure over the last few years. Guys standing reach is coming out shorter at the combine after significant growth, than it is at other camps. The only guys that seem to have the highest standing reach since 2012ish are the guys that weren't measured at the official combine.
Here is Zhou Qi this year, great example:
2015 Hoop Summit: 7'2 with shoes, 7'6.5 Standing reach, 9'6.5 standing reach.
2016 NBA Draft COmbine: 7'2.25 in shoes, 7'7.75 wingspan, 9'4.5 standing reach.
So he grew a quarter of an inch, his reach grew 1.25 inches, but his standing reach lost 2 inches? Yea, something is being done differently. Maybe the draft combine officials aren't letting players fully extend now or something, I have no idea. Thon Maker also lost about 2-3 inches off his standing reach compared to other places measuring too.
Anyway, the point is moot, standing reach arguments and such are about projections going forth. Pelicans camp has said and has cardboard cutouts of life sized Anthony Davis pictures, and he "reportedly" is over 6'11 and has 7'7+ standing reach now. I dunno if he does, and I dunno how much other guys have grown, because every team says their young stud is getting bigger and more athletic, but like I said, it doesn't even matter in this instance, because he's a substantially better guy at using whatever his length is to play big, and effect the game with shot blocking, rebounding, and finishing above the rim. We're past the projecting stage, Giannis isn't going to magically turn into a guy that can anchor like a big man, despite however much length he has, just like Durant didn't.
And yea. You can say that I'm acting like a child, but there is no "trajectory" or any objective measure that anyone can look at an even begin to argue that Giannis is even in the ball park of Davis after his second year, or in his 1 "down" year so far, and there is no reason to think the best he'll ever be is a season that was clearly his worst season due to battling injuries and the team being a wreck.
GIannis has a very long way to go before he's even as good as 20 year old Anthony Davis was, so stating with any certainty that he'll definitely better soon is laughable at best, and completely ignorant and homerific if we're being honest.
Edit: Wait, I just saw his post that said Davis hasn't been a superstar up to this point

The people defending Davis are clearly the biased ones here, hahhahahah.