I know that I should not comment on that, but I have tried Standard Notes for 2 years without subscribing because I can't accept paying $90 a year for basic features. It was also acquired by Proton which destroys its so-called independence. I use Joplin nowadays, and I have sync for $28 a year.

Feel free to downvote me for being off-topic.

To answer your question, E2E is mandatory for me in any sharing SaaS.