Several things from Google.
- Google Maps - none of the OSM-bases options are there yet. I need traffic conditions and good Android Auto support. At the same time I hate that Google Maps is so full of ads. When I search for "breakfast" and the top result is a sponsored result for Dunkin and the closest is 50 miles away...
- YouTube - the content is there so it's hard to go to an alternative.
- Google Photos - my issue with this is really more tied to Gmail. If I stop paying for more Drive storage for my photos, I will stop receiving email because my account is full. But I did switch away from Gmail at least.