Gmail absolutely undermines the openness of email. That's fine, it's a choice users made because they don't want to run their own email servers, so they offload it to Google. Google decides what to classify as spam. As such, if I stand up a new email server and start sending email to Gmail addresses, I am at the whims of Google deciding what email from me gets delivered.

The protocol is open and designed to be decentralized, but the system as implemented in the real world is fairly centralized at this point. Saying "you can run your own mail server" doesn't matter if virtually nobody actually does.

If the end state of crypto will just be a bunch of web2 style companies running centralized servers that (maybe) interact with blockchains, and we say "that doesn't undermine the promise of crypto, you can run your own node", I guess I'll have to agree to disagree.