I'll push back a bit, and you know my liberal cred.
First, I think WandaVision is thus far the best thing Marvel has ever done, so I'm not really in that first camp.
I also didn't think much of FATWS, but I didn't expect much from it as soon as it was announced, either. I just don't find the Falcon or the Winter Soldier to be compelling enough characters to carry a movie or a series, and combining the two didn't make it any better. As the story went on, it simply wasn't a storyline that I ever grew to care about. They're pretty low on the totem pole of characters I care about in the MCU, and FATWS didn't change that. I watched every episode hoping it would change my opinion of the characters. Instead, I mostly just ended up watching it to make sure I didn't miss anything important for the next series/movie. It was simply boring way too many times.
As "characters of color" go, I find practically every Black Panther character to be infinitely more compelling than either the Falcon or the Winter Soldier.
I haven't seen enough of the Loki series to formulate an opinion as to whether it will be good (though the first episode certainly seems promising), but as characters go, I have always thought Tom Hiddleston's Loki was incredible, and he's absolutely a character that can carry a series.
I don't think Black Widow is a particularly compelling character, but guess what? I also think Hawkeye and Ant Man are not particularly great, either.
I think perhaps I tend to prefer more "fantasy" type superheroes rather than just humans who happen to be good at fighting. I also prefer Thor to Tony and Steve, so maybe that's my thing.
If I recall correctly, you and I argued quite a bit on the quality of writing during the run of Season 8 of GoT, with you thinking it was good, or at least that we should just give it time, when it was clear from about 3 episodes in that it was going to be terrible, so let's not try to peg the lameness of FATWS on racism when it might just not, in fact, be as good as some other storylines.