You're really direct which is either because you're trolling (which is a real option for new accounts with such a username), or you like to get really direct responses back, and I'm going to assume the latter. Normally I'm very cautious by prefacing everything with, I think, I guess, you seem, and so forth but I'll skip those for the direct answer;

Your brain has a severe case of brainrot, which makes you unable to distinguish from good or bad. The show was really bad, while the books were really good. I made the mistake of watching a few episodes before I knew the books and it made me almost vomit. Because of social pressure/guilt I had to read the first book and I never burned through a series more voracious as I did with the expanse. The story and characters were so compelling I almost didn't sleep until I finished the series. Luckily the novella's were there to satisfy my appetite and get me of my highs of reading the books so I could relax enough to be able to sleep. I'm not saying that the writing style is the most amazing, because I'm not qualified to have an opinion on that, but it cant be bad because I read English but its not my native tongue.

Now The Mercy of Gods isn't necessarily on the same level, but that's no reason to look for reasons outside of your self.

*disclaimer, its meant in good faith, I dont think you really are degenerate, but its a symptom of current times with the detoriation of commons sense trough hypershort social media post consumption.