My UX of email has become so thoroughly irritating that I am to become an X user for most subscriptions. As soon as I can summon the energy to do it. One of the addresses now receives close to 1K a day of mails, mostly spams resulting from the proliferation you spoke of.
I am building my own new site, with a new domain name. One solution I have been contemplating is to merely disconnect the extant mailboxes, rather than forwarding them. Do email servers feel rejected? I hope so, I have never wanted so much attention.