You are forced to have a phone and there's only 2 bad choices.

Technically 3. Not much different from the Desktop situation. Just replace Microsoft with Google because Microsoft had the grace to bow out early.

Similar to desktop, I choose the middle ground between true freedom and walled garden. At least you Can de-googlefy 95% of Android. More than you can de-microsoft Windows.

3?

Samsung sells phones with their Tizen operating system.

Of course you could also buy one of the purism phones, jolla is apparently planning to ship phones too.

If you're willing to flash the phone, you can run postmarketos on loads of devices too.

I suspect the vast majority of people who are invested enough to want to avoid Android and iOS have the technical knowledge to install postmarketos.

And then your bank app, your government app don't work and you need a 2nd phone. Hence why there's only 2 choices.