Proton is privacy friendly, that is for sure, but apps need a lot more improvement. Even today, I received an email from a known airline company regarding to a feedback, and mail body was empty on my iPhone app. I was able to read it from Windows app. It wasn’t the first time that this was happening. Previously Proton was saying there is PGP encryption active between SL and Proton mails, that was why I wasn’t able to read some emails, but this one came directly to my mailbox without SL.
Privacy is needed, and a most welcome thing, but it shouldn’t hinder my daily tasks.
Even though I hate Microsoft, they seem to be most convenient and secure option. Plus business products are much more different than normal M365 personal products, including privacy and security settings. I know they are not as privacy friendly as Proton but still good (I think)