Also, people (including me) think that some newsletters, some bills and receipts are not very personal, so people don't care.
I have two main addresses, one is from a local provider and my all financial e-mails and other stuff is coming to that e-mail address, however they don't encrypt anything.
I also just got a free Proton mail, and will upgrade the account when I'm a little better off. Paid e-mail addresses are not meaningless, but they're harder to justify in most people's eyes.
BTW, I never store anything which makes me uncomfortable, anywhere incl. my brain. That's a much better way of living. Not that privacy conscious people is hiding something, but that's my policy.