Unfortunately, "extremely expensive" and "high-end" aren't really synonyms, thanks to, y'know, bitcoin. Of course, I don't disagree with your argument that having to buy a GPU just to ensure your webmail does what it's advertised to do is, well, dumb.
What I don't know is what the LLM even is. Did they just tack on Llama to their webmail app and call it a day? Did they train a model? Was it trained on emails? If so, whose emails? What an advertisement that would be: "Use Protonmail to encrypt your emails so that companies like Protonmail can't use them to train an LLM."
I'm so certain that ASI is so soon that I'm going to go hiking in the woods in the dead of night with no supplies and not tell anyone where I am.