On Google's Youtube to post links (like in video descriptions, etc) you have to pay by adding sellable/monetarily valuable personally identifying information to your account like a phone number and ID. Otherwise even with a google account from 2006 in good standing you can't post links anymore. Attempts to edit old video descriptions with HTTP/S links (from before the policy) also don't work.
I'm not sure a phone number is particularly valuable. It is a decent way pretty much ensure that you aren't a bot, though.
I don’t know whether to be glad about this because of how horrifying YouTube’s spam problem is, or annoyed because it isn’t helping since their comments are what’s full of rampant fraud spam of every kind.
Honestly, the best thing YouTube could do to help protect users would be to shift to moderated comments only. If the video creator or their designated moderator doesn’t choose to explicitly show a comment, it should go in a black hole. Or even better, offer a service for a small fee relative to your channel’s revenue, which uses a Gemini flash model to approve on-topic comments. Creators can choose to invest either their time or their money, or just have no comments.