I don't remember seeing those claims, but yes, you're right.

One way Nostr helps fixing spam is by making it obvious that spam is a thing, instead of trying to hide it behind a curtain of failed KYC-walling of platforms. All these platforms, X, Telegram and others, have all sorts of constraints of whom can create accounts, and yet they're full of spam and users have no alternative other than to eat the spam and click "report" buttons because everything is assumed to not be spam.

The empty X account I've created after deleting my old account just to be able to read links people send me has now over 300 followers, all of which are bots, and I didn't even do anything to signal I would be a worth scam target.

Meanwhile on Nostr everything is (must be) assumed to be spam but data is widely available and simple solutions can be implemented by anyone, like the ridiculously obvious (in hindsight) "WoT" filtering that works in 99% of the cases, but there are many other ways.