Authy 2fa doesn't work on GOS because of Play Integrity. GOS has been talking with regulators in the EU about this.
An Amazon delivery locker doesn't open without Sandboxed Google Play installed, I've switched to post office deliveries. I had to change my account user name to my actual name ( my name is extremely common so no big deal really) but at least I don't have Amazon's shit app installed anymore.
Google Pay doesn't work.
Android Auto is hit and miss.
There tech support is also fantastic. I had an issue yesterday morning, it was fixed by the afternoon.
I use VoIP MS and have two way texting. They are very much KYC, extremely inexpensive, and the service works very well. There is an unofficial app called "voipms sms" on F-Droid that I found buggy but it seems to work for a lot of people. I use Sipnetic for voice calls and sms. So many options for routing calls, dealing with spammers.
If you are looking for more of a private service JMPchat, they do cost quite a bit more but have no interest in your personal information, they just want money.
Not always, unfortunately.