I have pretty heavily dumbified iPhone just for the camera and music. I wish there was a dumbphone with a decent camera with telephoto. I have standalone camera but with a decent lens it's just too big to have on me at all times and unfortunately I like taking photos.
Base install of Graphene on Pixel 10 is pretty close to dumb-phone (I speak from experience). Just get the APKs of Signal and Google Cam (or just use Graphene's cam app, it's not bad, supposedly). Pixel 10 has 3 camera, wide/normal/tele. Pretty decent imho.