There used to be a way to make Google accounts with no number but that’s probably been patched. I generally refuse to add numbers if I can help it.

Proton, Mailbox & fastmail are all good options. Best way to avoid it is self-hosting but that is beyond most people (as in time-consuming).

If they made it so your average joe could contribute to the Fediverse with their own hardware I’d contribute. Tired of seeing social media be owned by Billionares.