There is a simple way though : have the ISPs provide all of this. If they can provide you a personal website, an email account and a NAS, they can also provide you a a personal website and an email account ON that NAS. (Especially now, with IPv6.)
(Which of course assumes that there are laws in place against lock-in, just like there are already laws in place against lock-in for your pick of ISPs and obligations for mobile carriers to transfer your phone number to another carrier.)
I think this only shifts the problem, the whole idea with the internet is a distributed network of computers that talk with each other, and if the computers at the edge (end users) can't do that, then it's no longer the internet, it's something else, more akin to cable-tv where there are "providers" and "consumers". The playing field stops being level.
Ah, I took it as you suggesting the ISPs providing VPS services for people..
Thing is, that edge infrastructure has been there from the beginning of broadband and is only recently beginning to slip away, with the advent of ISP NAT, agressive IP rotations, blocking of ports and not providing public IPs at all.
(Which of course assumes that there are laws in place against lock-in, just like there are already laws in place against lock-in for your pick of ISPs and obligations for mobile carriers to transfer your phone number to another carrier.)