House of Dragons started slow, but so did Game of Thrones. I think Matt Smith is a very good actor, but he as Daemon Targaryen just doesn't work, imo. I'm not too disappointed in the show because I didn't expect much from it anyway. I certainly wouldn't call it a bad show.
Now, Rings of Power, with a billion-dollar budget and incredible lore that has stood the test of time, you'd think that would be great. Or at least good. But it's actually worse than mediocre.
It's funny that Rings of Power has been criticized from the start for gender and race swapping, and from the start the cast and producers often made the swapping the most important thing they cared about, but now that the show is doing poorly the cast and producers and media are putting the blame on the "bigoted" criticizers,
even though I've seen plenty of the loudest criticizers praise the acting and scenes of the black dwarf lady as being one of the only decent parts of the show, while putting most of the blame on the casting and behavior-changing of the main character Galadriel. She wasn't race or gender swapped but is written very different from the books, and written poorly and is an unlikeable character.
Rings of Power is similar to the new She-Hulk show, (and numerous other examples). The creators and actors basically hate the fans. And they'll tell certain demographics of would-be fans "this isn't for you." And then when those people don't watch and the show does poorly, they get told they are the problem for not watching.