KeepassDX (Android) has a really nifty keyboard feature which allows you to even put passwords in apps, which the regular Firefox Sync doesn't support. Maybe that's the use case which makes you do the switch?
(I've used it quite successfully when it was in a separate app called Lockwise)
There is a separate autofill feature, but that works quite rarely, maybe 10% of the apps support that, but that makes things even easier.