Your question is a bit all over the place.

If you’re just looking for big amounts of storage, look for refurbished HDDs (4TB, 12TB, something like that).

Ah yes, true. But it is a whole year, so you’d only need to login once a year.

And what would be a situation where you have to enter a phone number? I only know it’s optional for account recovery.

As far as I know they delete the account if you don’t log in for a few months.

I mean, without the additional requirement Proton may be sufficient.