I have switched everything to privacy alternatives is it safe to delete my Google account or is it needed for some android features also if I delete my account does Google delete all my data if not, can I request the deletion of my data under the GDPR
LOL No, they never delete.
Harddisks are cheap, especially when you buy thousands of them.
What you should do: a few days before you set the deleted flag to your account, clear all the data fields that can be empty, and change the ones that cannot be empty. Change them to contain only nonsense. Everything. Your name, your password etc.
There’s definitely history for this. Don’t think it’ll achieve much.