Depends on the adapter you get.
LA-EA1: Partial compatibility only. Won’t autofocus with older screw-focused lenses, and won’t work in full frame cameras. Only does contrast-detect AF.
LA-EA2: Works with all lens types, but only compatible with crop cameras
LA-EA3: The LA-EA1, but with full frame compatibility.
LA-EA4: The LA-EA2, but with full frame compatibility. So this is the only one that really gives you full compatibility.
Notably, the LA-EA2 and 4 cost you something like a quarter stop of light, the mirror inside is crazy delicate, and it makes your battery life even worse.
Plus, the LA-EA4 costs $300 vs the Canon adapter’s $99, and the canon adapter is even included in the base EOS RP bundle which means you get full EF compatibility right out of the box.