I’ve been using Proton for several years now, and paying for their Mail and VPN features. Proton Mail is definitely better than Gmail, but other than the privacy features, it’s just a basic email service. Their VPN also is just a basic service. If that’s what you need, then by all means, I’ve always had a good experience with them.
That being said, I do run a competing email service called Port87 that (IMHO) has better features for organization and spam protection, so take what I say with the knowledge that I am technically their competitor (although my user base is tiny compared to them). Really, I see them more as an ally against Gmail and MS Exchange, because I’ve never experienced any sort of anti-competitive behavior from them like I have with both Google and Microsoft.
Supporting smaller players in the email space is what keeps email open, so the more people move away from Gmail and Exchange/MS 365, the better.