Yes, I bought a Pixel 6 specifically to run GrapheneOS. I can proudly say that every single app on my phone is open source, no GSM and no Google. I don't really mind paying a company like Google for the phone, I just don't want to hand them my data.
Yup same here. Two profiles, one is my daily driver and open source, they other is for the few apps I need with Google services. This is the perfect compromise between what I want, and what I need.
for navigation maps, you can use openstreetmap like magic earth and organic maps
if you think osm doesn't have enough data of your area, then you can use herewego maps, its another proprietary map, but is a bit better than google on privacy
The only thing I personally use out of all these is online banking and I do that from my PC at home. For reviews on Google maps I could theoretically just use it in my browser.