The intention isn’t to make mediocre shows. The intention is to make a show which draws an audience, and Star Trek shows start with a decent base audience to make it worth trying.
Discovery did not work for me in the same way despite me usually liking those less episodic plotlines.
Now that the series are basically only available on streaming through CBS/Paramount I don't know what syndication gains are being made, but I'd guess a huge percentage of the CBS/Paramount streaming subscribers are staying subscribers for the huge Star Trek library. It's an anecdote but the last time I quit Netflix was when they lost Star Trek and I realized I was basically only hanging on for Star Trek episodes (after about a year and a half I resubscribed for other content).
That said, there is a case to be made that Star Trek is now more than just TOS/TNG/Voyager, and it already was that after DS9. So I don't begrudge fans of the dark, morally gray, against-a-backdrop-of-war stories getting to see more of that in new Trek. At least the animated shows (Lower Decks and Prodigy) keep the optimistic spirit of Starfleet alive, so there's something for everyone.
DS9 ... was odd in the spirit regard.
The early slash fiction writers (almost all women) in the 1970s more or less viewed the science fiction elements like the Enterpise and the Federation as distractions, and got Kirk/Spock away from them as soon as the could to focus on their relationship. In other words, they were inspired by the close, John Ford-like camaderie between the two characters (or, if you choose to believe so, saw the clear sexual subtext below their heterosexual veneers) and used it as a springboard to tell the stories they really wanted to tell.
Only to a certain subset of "fans" who have made hating Star Trek a part of their identity politics, and a grift on Youtube. They've even started to hate Strange New Worlds, even though it should be everything they wanted.
In actual objective reality, each of the new Trek series has been highly successful.
...The only reason anyone could dislike modern Star Trek: Because they want to </s>. No, I actually want to like the new Star Trek. I just found that to be prohibitively difficult.
> They've even started to hate Strange New Worlds, even though it should be everything they wanted.
Except that it wasn't. It feels like a modern Marvel film masquerading as Star Trek. With sassy Mary Sue characters that just quip back and forth sarcastically. The dialogue is honestly terrible.
> In actual objective reality, each of the new Trek series has been highly successful.
On Rotten Tomatoes Picard has an audience score of 57%. Discovery has 37%. About what I expected. Strange New Worlds is doing well though. I'm not upset that other people like it. I'd consider giving SNW another go, but I won't waste any more time with Picard or Discovery.