First, Apple doesn't show ads anywhere in the OS. If you're talking about ads served in web pages, that's another thing.<p>The only Linux phone I know of that's actually purchasable for humanly reasonable amounts of money is the PinePhone. Everything else I've seen is yet another Android, and Android is tied to Google.
I've been very happy running GrapheneOS on a pixel 6. It's based on AOSP (android) but includes no Google software.<p>App compatibility is good, with some apps not showing notifications without installing Google Play Services (which Graphene allows to run sandboxed like other apps). Ive been running without play services
I think rather than looking for a Linux flavour you want to look at various companies business models and size to see if it can sustain the ongoing cost of releasing and supporting a phone, OS, security patches etc.
So far, Apple still has a pretty low % of revenue coming from ads.
The PinePhone (and the PinePhone Pro) are close to daily driver status, but I'll also make a plug for SailfishOS.<p>I've been using SailfishOS on my Sony XA2+ for nearly three years and it's brilliant. Using the licensed version, I can also run Android apps as long as they're not dependent on Google services, although I prefer the UX of the native SailfishOS apps.
Does it need to be GNU/Linux, or would you accept non-Google Android? Because if you're willing to make the sacrifices to do GNU/Linux on a phone, LineageOS without gapps is probably an option.
This will probably sound counter intuitive, but my Pixel on Google Fi has the least bloatware and fewest ads I've known on a phone. The alternatives all seem like a downgrade in hardware or UX. I put up with lower quality coverage, but for the most part it doesn't matter because it uses wifi 99% of the time.