The Otsutsuki might be fine and all provided their execution is done right. So far they’ve seem simply to be the new clan to replace the Uchiha villain clan. It feels like they are just going to try to do the same thing over and over. That is produce a fruit eat it, enslave planet. Not sure what else they can bring to the table other than over the top Jutsu.
I’m actually more interested in where they going with this ninja Vs ninja tech and what Kawaki’s role in all of this means.
I see what you are saying, but you are going just based off of the few Otsutsuki villains we've seen this far, and those villains had exceptional circumstances (both in universe and out of universe) that affected how their characters were written. For example:
Kaguya was implied to have run away from and betrayed the Otsutsuki clan. In the anime, Momoshiki/Kinshiki even imply that Kaguya violated clan law by not reporting her findings regarding Earth to the king.
This would mean that Kaguya's goals that we saw in the manga wouldn't reflect the overall goals of the Otsutsuki at large. Her goals would just more so be motivated by self preservation and not letting the Otsutsuki catch her and take her power/life.
The series has actually already confirmed what I'm saying by noting that Kaguya was preparing the white Zetsu army in order to fight off the other Otsutsuki. Even in the anime filler arc, Kaguya was shown to be paranoid, always looking up at the sky for the Otsutsuki.
In short, if you found Kaguya's motives to be a bore, it is because her motives were more so self preservation rather than anything substantial.
As for Momoshiki, any boredom that comes from him is due to a fact that has more so to do with real life production (of the series) rather than in universe factors. There is something that you have to remember:
Boruto Naruto Next Generations wasn't originally intended to exist. The original Boruto movie was originally going to mark end of all things pertaining to Naruto (aside from games/DLC/novels/merchandise/etc...).
Momoshiki was only created and introduced for the Boruto movie. He was just meant to be a villain that paralleled Boruto's lazy "I don't want to work hard" attitude, while still being able to give Naruto and Sasuke a good fight. It should also be noted that he wasn't even the focus of the movie until toward the end.
In short, Momoshiki was originally only created to be a villain that could parallel Boruto's laziness and also give Naruto and Sasuke a good fight for about 30 or so minutes (in real life time). Therefore, there was no time or need at the time to give Momoshiki some deep story or ambitions. He was just a parallel. He was not like Madara and Obito who were actually meant to have deep stories and motivations.
That is why Momoshiki's character/story lacked depth.
Now it's true that Momoshiki later appeared in the manga, but that was just for rehash of the movie, so in essence, he was still just the same movie villain parallel.
Also, like Kaguya, the anime is suggesting that Momoshiki is trying to do his own thing as well, thus going against the law of the clan.
In short, exceptional circumstances and production circumstance made Kaguya and Momoshiki the villains that they were. I don't think that people should really judge the Otsutsuki based on these two arcs because the circumstances of these two don't really reflect the general circumstances of the Otsutsuki clan as a whole.
In both cases thus far (Kaguya and Momoshiki), Kishi was just adding finishing touches to the NV, not intending to go much further with it.
Now however, we have a full on manga where these Otsutsukis are actually thought about from the get go and not just finishing touches or parallels.
Do you see what I'm saying?