better practical compatibility for sure. Of course not literally the entire back catalog of old legacy smartphone apps are still supported but probably like 99.999% of apps people still use are supported on 99.999% of phones people use. 32-bit app devs have had 10 years to update to 64 bit, and most managed it within the first couple. Also the kind of major compatibility jump as with 32bit>64bit should be fairly infrequent, not like every console hardware generation.
compare that to game consoles where the last gen could be cut off from new games at any given time, and next gen is a crapshoot whether the manufacturer will support backwards compatibility.