Proton does offer what is essentially a self-contained PGP portal. You send anyone an email and they get a "hey, this is me, open the message below" thing and then a link to a message that's hosted on Proton servers. So your Granny doesn't need to set up a public/private key pair, you can just send the encrypted portal option.
No idea of Tuta or others do this.
Plus, no matter who you chose, you personally aren't feeding the Google algo. You can do what I do, which is you leave all the hyper data hungry services in the data eating world, just feeding on each other alone. Then you have real conversations over email or fediverse.