Couple different ways to define ace. This is a good although dated article from about 10 years ago and, especially for prospects, I think it's pretty good way to judge them.
Since 2017, Berrios is #1 in the AL in innings pitched and games started (Kyle Gibson is second in both). And Sale, Verlander and Cole are ahead of him in fWAR (he's tied with Lynn). If we include NL pitchers, he's 8th, 9th, and 15th in IP, starts, fWAR. So he's been pretty good.
I'm in the camp that thinks there might only be a handful of true aces at any time but that pitching in the AL is a lot harder than pitching in the NL. I don't think Berrios is an ace but he's a #1 pitcher on many teams and, if he was your best pitcher, you could still win in the post-season. (He was pulled after 88 pitches and 4 innings in 2019. In 2020, he was pulled after 75 pitches in 5 innings against the Astros).
He sorta reminds me of an "in his prime" (79-87) Jack Morris. An innings eater who will give up a few more runs than you'd expect but is really valuable to the rotation and the team. The eras are different, obviously, but it seems similar to me.