Techies live in their own world
I fully agree with all the comments about controlling your device. That option should be available to those who can take advantage of it.
And that option IS available...though you have to do some work to get there. Personally, I run a rooted device with LOS 16 on it. No bloatware, full control.
But most people can't do that. The subject is complicated, ever-changing, and requires a great deal of attention to keep up with it. Also, while the only way to fully secure an android is to first root it, once you do that it ceases to be an appliance and becomes a device that you have to manage...and you can easily brick it. This is too much for most people.
The solution - if there is one - is to change the marketing model in a fashion that discourages these abuses. The EU privacy laws are a decent start in that direction, though there needs to be some heavy fines for non-compliant companies.
And as for whether Google Play Services is needed on an android to retain functionality...
The phone will run just fine without any of the google stuff on it. But Uber will not work unless Google Maps is present. And Signal, of all things, won't work without a fully enabled google play services. I was forced to add google stuff to my phone if I wanted to use these apps. I make heavy use of Signal, and from time to time calling an Uber is very convenient. So... Shrug.