I don’t understand why Google didn’t just made Android closed source. They would’ve made custom roms impossible and therefore more able to control and spy on it’s users. Why did Google made Android open source, while Microsoft’s Windows is still closed source to this day?
If your use case revolves around a limited amount of apps and features, I can see how that would work. If you travel the world, experiment with new services etc. you might end up that the only way to obtain the required service or information is an app, which mandates GMS, which goes for an absurd amount of programs, and if you don’t have that, that’s it. No access to the service or information in the middle of the road and sometimes nowhere. I used a degoogled system. It is everything, but certainly not everyday usable. As a secondary phone perfectly fine, but not as a primary.
Of course you could start a debate with the developers of why their public or event service relies on Google, but good luck until that is implemented when you are locked out right now.
I can tell you why app developers are using Google services.
All this leads to a situation where using alternatives is just too expensive and will increase your development time noticeably (and that will be expensive too). Large companies can bite the bullet and just write off the losses, simply because they don’t like Google or whatever. But for a smaller developer that’s a death sentence. And if you’re creating a free app - just forget it.
You just have to commit and be willing to selfhost stuff to replace stuff. If you are unwilling to selfhost then degoogled is harder