That is indeed a weakness of Web of Trust.

Thing is, this system isn't supposed to be perfect. It is supposed to be better, while worth the hassle.

I doubt I'll get vouched anywhere (tho IMO it depends on context), but I firmly believe humanity (including me) will benefit from this system. And if you aren't a bad actor with bad intentions, I believe you will, too.

Only side effect is genuine contributors who aren't popular / in the know need to put in a little bit more effort. But again, that is part of worth the hassle. I'll take it for granted.