I just used a Huawei phone for like 2 year without GMS, but you and I are not 99.999 of the general phone users out there.

I used Aurora store to access the Playstore, youtube vance to play youtube movies. For the rest i only use Facebook Messenger(for family), whats app, Telegram and my banking app doesn't need GMS to function. Those messenger app have their own notification services so not completely dependent on GMS stuff. For the rest i'm more interested in camera specs and not really in mobile app ecosystem outside of those couple of apps i just need to talk with family and friends..

It is totally doable but don't think 99.999 of the phone users will take the effort to find everything out.