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
Yes, you can completely abandon Google services or directly use one of their clients. For example: instead of Google Play, you can use Aurora Store; instead of YouTube, you can use Newpipe, and so on. Besides, Google does not respect privacy; it makes a living by spying on us and more or less knows what you are thinking.