That's exactly the reason why so many people prefer giving up their data, their privacy, their freedom.

Personally I'm happy to pay proton a few bucks a month to not have to give up those things.

I'm not criticizing those that do, just that given my financial situation the trade off is simply not worth it.

Hushmail was great for me, until I couldn't reclaim my inbox after the subscription expired (but there's no free option).

Other services deprecate or get weird. Hopefully Proton keeps going in the good direction.

Yea I’m in a position where I can’t splurge on things at the moment and basically I would be simply paying for email filters since Proton’s free tier only lets you create one.

Paying for a service that you use on an ongoing basis and that is very important (like email) is probably the best possible choice, since it aligns what you're paying for and what the company is working on. In the model you suggest the core service will atrophy slowly because the money is in the add-ons. This is why I'm happy to pay annually for my Fastmail account.

Agreed, even though I use the free tier. Ideally I'd host my own email server but that's not an option for me right now.