Frustratingly, the two are good at different things.
Apple Maps is mostly better at announcing driving routes. Routing quality is similar - they provide different, but similar-quality routes. Public transport routes are superior because - shockingly - they seem to have more accurate data than Google Maps. Google Maps is still superior in the specific location of a business within a narrow area. Apple Maps has more errors where the marker is on the building, but Google Maps has it at the entrance.
At the same time, local search is terrible. Their partners’ and their proprietary data is inadequate and it seems businesses don’t know they could/should care and don’t maintain listings. I’ve submitted several changes in my local area and while they are usually accepted, some of them ended up reverted a while later. They seem to be working on this and hopefully they’ll eventually catch up - but I’m not sure how, if businesses don’t maintain their listings!