I'm glad to see IPv6 adoption growing, and that one of my home ISPs now provides IPv6 that the router I have connected to it autoconfigures without too much digging, but some of your points aren't meaningful to a "non-technical end user", and some aren't a clear benefit of only IPv6...
My dad uses AOL (webmail, not dialup), he's younger than 70 but not by much.
However, my younger brother also uses AOL... about a year ago he got a gmail account, but last time I sent him mail at his gmail address, he didn't respond, and when I called him he said he hadn't seen the message. Then I re-sent the message and CCed his AOL account, he answered from there. So, I haven't seen the UI myself, but I'm sure it's "good enough". He's hardly a tech newbie; has a BS in physics, currently in grad school.
+1 on the self-hosting. For outgoing e-mail there are various "email send" services aimed at transactional e-mail from cloud-hosted applications but that are easy enough to point Exim or whatever at. For incoming I guess it would technically be "running a server", and might be iffy on dialup, but I've never used an ISP that actually blocked incoming port 25.
"Home life as we understand it is no more natural to us than a cage is to a cockatoo." -- George Bernard Shaw