You can't make the argument that a mutt is universally better than a pure bred either. A mutt is a random assortment of components some of which are not ideal for life in human society or what you want in your particular pet.
Temperament is the most problematic because you can get a bad mix of drives and intelligence.
I think the question is whether what you get by picking the components is worth the cost? You won't answer that question with anecdata from a farcical comedy video. IMO the video does a lousy job of making any kind of useful point. I suppose it's good for awareness.
The video makes the exact mistake I warned about. You can't conflate what bad breeders do with what the outcome would be if all breeders were forced to conform to better standards or you find a breeder who breeds the way you want it done.
Straight from the video, breeders breed parents and children and siblings. It's sadly common that it will have happened at some point with many breeders. It's also insane and if you buy from a breeder that does that you have done something wrong.
If someone has some well thought out research comparing the outcomes of a known strong set of well bred dogs from a breed designed to be functional (for some definition) to a set of mixed dogs then we might have a way to quantify exactly what the cost is. Anything else is conjecture.
There are other strong arguments to be made for adoption and mixed breeds. Possibly for people unable to muster the expertise to find a breeder. I still think it's conjecture, but at least more reasonable sounding.
Some of those arguments apply to human breeding, but try having that conversation ;-)