How much should I care about "relevancy" when building backlinks?

Relevance matters.....

But

My competition has links from alsorts of non relevant sites.

The sites linking to some of my competition have no relavance but they have high DA & PA.

And I haven't been able to outrank my competition even when buying, relevant niche edits and guest posts. (Both with over 50 DA.

This is why 2021 is going to be the year of spam for me.

If you are going long time. You should only look for relevancy

I personally go for relevancy.