Tricky for TV, I guess.
Like in Dune where the whole series can be summarised as "we have all seen the boy that fights the evil emperor and wins, but what happens then? Does the boy then become the evil emperor and restart the cycle?", the point of the WoT books is not the people, but the cyclic nature of things: the characters are just a means to illustrate the complexities of going round in the circle (and the "magic" schema is an attempt to distance the saga from all the others that do the same). It is difficult to see how this can be made for the screen (like Dune), because on the screen the makers want the audience to care for the characters and, as you note, to identify with the characters; hence we have to have one of each ethnic group, gender and religion in every group.
GRRM's adaptation solved the problem by regularly killing folk - often while they were copulating, so people were invested in the experience without really caring about the characters - the makers' problem in that case was guessing the ending (which was doomed to fail, as there won't be one. GRRM has painted himself into a corner, and is stuck)
In GoT (the tv series), there were characters that I did care about. Not here. amazon prime is capable of producing good series. I'm watching The Legend of El Cid, which is not bad and the main actor, (El Cid) Jaime Lorente has sufficient range that you care if his character survives all the plots against him (he plays a genial doofus in Casa de Papel). There's kind of heavy handed character development (bad guys about as subtle as Snidley Whiplash) but you care. I think that perhaps the problem with WoT is that there's too many moving parts, too many characters, so it just doesn't hang together, despite great costumes, really first rate CGI and probably actors who can act but just have bad scripts. Because it's generally kind of lame, I tend to watch it when I have nothing better to do. So the continuity is a problem.
I've only seen the first Dune movie, which was camp and kind of embarrassing. I'm sure the more recent ones are more beautiful and compelling. But, if I remember from the book the main guy who figures out how to ride the spice worms ends up saving people and then becoming an oppressor? Right? I'm still kind of pissed at the degeneration of GoT in the final season where people just got personality transplants to become new characters and behave in ways that beggared belief, and ended up like some kind of summer camp meeting. So that's another WTF candidate.