TL;DR No it’s not.
I doubt the trend will reverse with networked technology of any kind, no matter how much a bunch of nerds on HN want it to. The truth is email has been centralized the day aol came on the scene.
This is the real problem with decentralized anything, coins, land, water. If you can control the majority of it, you can change the rules of the game. That’s what email has come to, a few major players and the rest of us.
Try to set up an email server on your own with mailinabox or something, send an email to a gmail address. Spam. Right away. You could say it was the spammers that did this, “they pissed in the well!” and ruined it for everyone. the reality is this would have happened sooner or later for a good reason like spam or a bad one like profit.
There’s not much we can do except try a few different IPs and keep building reputation and maybe just maybe take back a large portion of email servers and clients for ourselves