Buy a last gen Pixel used from a private seller maybe like on eBay and install GrapheneOS OS on it. If you don't want to mess with a lot of stuff, you can use the main profile for foss apps and open another user in which you install sandboxed Google Play services and gradually switch to foss apps more and more
Anything and everything else is objectively worse than an iPhone
And that kids, is why we are pushing for Rust in the Kernel