> But an IT savvy person should consider having their own email domain.
Having email domain is different than hosting your own email servers. And even that - why would I care so much? There are plenty of articles here on HN of people telling how hard it is to host your own email servers.
Plus, tech-savvy doesn't mean I want to waste 2 hours a week updating managing servers etc., while I could maybe learn ... "Flutter"? Or technology X. Or something else completely different.
In general, assuming what a group of people should or shouldn't do seems pretty naive to me.
> if you don't pay for the product you are the product.
I pay for Fastmail and it works. Until when? I can't tell - I hope they don't go bankrupt. But they offer a good service, decent price, and it gives me 1-2 hours of life back per week or month.
I understand your counterarguments, however nowadays there is enough variety that enables us to use products and services for quite some time. Even open source can get you into "vendor" lock-in, especially when a tool or product doesn't evolve anymore and the community doesn't have interest or manpower to improve it.