Highly depends on your threat model and what you are using email for. Using email for actual communication, besides creating accounts or reaching out for a random customer support, is a big mistake in my opinion. 
For me it's only about escaping data scraping (regarding email). I can rely on Proton regarding security without having to worry about any new backdoors or whatever that I would have to maintain/fix. They don't sell my data to bigtech companies even if the gov might get access in special cases (at least I think so). So why shouldn't I use Proton?  

 I agree email sucks.  And I agree it depends on the person.
But many businesses require email for sales.  So for small businesses, who want the freedom and privacy, then this goes excellent with the other VPS services such as cloud docs and chat.