Proton Mail is free and provides a lot of value, but I agree with @Cyber-Typhoon that there are enough limitations to it that, IMO, it becomes impractical to use as one’s default email if you’re not on a paid plan.
I only started using my Proton address as a default once I upgraded, and that was 3+ years after being on a free plan, during which I rarely used my Proton address, partly because I didn’t want to expose it to SPAM.
I think one of Proton’s goals should be to gain enough paid subscribers to make more and more Proton Mail features free.
However, there are 2 things that Proton does that to me smacks of enshittification and dark patterns.
1) Not allowing multiple subscriptions under the same account.
I’ve talked about this before here and here.
2) Adding friction/Removing Features from Proton VPN that were once free
You now have to wait 2 min every time you want to switch countries in the free version of Proton VPN. It wasn’t like that before. This is the textbook definition of enshittification.
To me, both of these practices are unacceptable and deliberately punish users with modest means.
The freemium model is a good model, but like I said earlier, IMO, privacy companies should work on attracting enough paid users so that they can improve the free version of their services and eventually make their paid tiers cheaper.
There is a right way and wrong way to do freemium.
I have personally never upgraded to the paid version of a service if I thought the free version sucked. I need to be impressed by the free version to want to upgrade. And there are many services whose free version satisfied me so much that I never felt the need to upgrade (Evernote) or I eventually did but only after a good couple of years. And I have never allowed myself to be bullied by companies who remove free features. Never. That’s why I never paid for Evernote and switched to Notesnook.