For me, it’s multiple machines. 2 iPhones, 3 iPads, 3 laptops, a couple of raspberries, and a couple of work machines. I tried to do it with a synced KeePass DB, but getting it to synch properly was nightmarish.
SyncThing may also work for a open source solution, but doesn't have that nifty latter option I stated above, at least not out of the box.