You can't decrypt if you don't have the private keys. I mean, these people aren't Zoom, who keep the same private keys on the same server as your data. We can't handhold these tech giants and baby them. They know better. The data should have never been stored in plaintext. And, if it was or is encrypted, they should never have access to the private keys. Why did they do it? I'm assuming because they got greedy, and they wanted those prompts for their own internal training.

Not that. SSL is just transport-layer encryption, once the information is on the server it's plaintext.

Everything uses SSL or, more accurately, TLS. Very few things are E2EE. Consider Signal - is Signal equivalent to Whatsapp because Whatsapp using TLS? Of course not.

If you have data in plaintext on a server, you should always assume that data lives forever. You might be wrong sometimes, rarely. But usually it does live forever. Most delete buttons don't even actually delete anything.