If WWE had simply let wrestlers do indy appearances or wrestle in Japan, Bryan might be signed with them right now. He's really advocated for added freedom for the wrestlers (see my attachment).
If Danielson has signed with AEW, this is much better for this back nine of his career (now that WWE gave him the added exposure (and money) he needed). Bryan was simply too good for WWE, with the talent he still has left in the tank. With Omega, Andrade, PAC, Fenix, Pentagon Dark, Darby, Cassidy, etc....endless amount of great opponents, and that's not even counting Okada and others he could face in Japan.
Going to AEW would be kinda like Bryan going to somewhere in between big-exposure big-money WWE & his roots in ROH, a perfect sweet spot for him to land.