It didn't work before
The idea of a Star Trek anthology show isn't new. Technically, we had one. Remember Short Treks? No one really watched it. It was this weird, inconsistent, and at times, unwatchable mess of a series. It had no rhyme or reason, no consistent ton,e and no real reason to tune in week after week. Some episodes were supposed to be super serious and thought-provoking and then others were supposed to be super humorous.
We'd find out about death and turmoil on catastrophic levels and then the next episode would have a man being killed in the same of science, but all as a lark. It was a whiplash of events that didn't' build to or offer up anything of importance. Nothing, absolutely nothing, in Short Treks, made a dent in the Star Trek mythos.
That show could be dropped from the canon of the franchise and no one would bat an eye at losing it. It did nothing to make the show better. Now, we're supposed to believe that a longer version of Short Treks is going to be successful.
Why? There's no proof it'll work.