OSM lacks a lot of details that completely change how you'd move from point A to point B (I was missing overpass bridges and crossable paths in residential neighboorhoods), and point to point navigation is also not great. Then it completely lacks all the more commercial features Google has built on top of Maps (store details, position sharing, timeline etc.)
On sheer readability I also prefer Google Maps, but I've been using it so long that that might be just familiarity.
I wish I'd like OSM a lot more, but every time I ended up back to Maps for a reason or another.