Who is this "we" you speak of? Joking, mostly, but webmentions are still a thing and getting a touch more popular in some of my circles. I know not everyone liked them even back when they were new, but -- with the proviso that they need to be checked for spam just like conventional comments -- I generally found them to be have a better signal-to-noise ratio than all but the rarest (and usually most actively moderated!) comment sections. The effort in setting up a blog capable of receiving pingbacks/webmentions isn't that high, but it's higher than drive-by trolls and cranks are likely to want to put in.

Maybe now that they have less support, but back then it was only spam IIRC, or the same blog posted 10 times

I think webmention implementations tend to be smarter -- probably not universally, but generally -- about de-duplication than the older pingback implementations were, so you rarely see that weird flood of multiple links to the same place.