No, and maybe.
“Censorship resistance” qualifies anyone’s ability to publish anything at anytime, without concern of being “banned”.
“Spam proofing” refers to an END USER’s ability to filter their OWN feed as per their OWN content wishes.
Nostr, as freedom tech, needs to shine in both of these abilities.
MAYBE proof of work solves for spam resistance, but maybe sometimes it doesn’t. There is no silver bullet, and the best (open source and client agnostic) WoT algos will incorporate many user configurable filters in order to accomplish this task.
My Grapevine is building better WoT algos for Nostr. https://grapevine.my
People sometimes forget that freedom of speech doesn't necessarily mean that everyone has to hear or read what everyone says. People should also have the freedom to configure their social experiences however they want. This includes muting or not seeing anything that I don't want to see. The spammer wins because they can spam the network. I win because I have them filtered out and don't see things I don't want to see. It's a win/win situation if everyone is given the freedom to do whatever they please here.