If the show reaches five seasons, it’s done incredibly well in today’s environment. Especially on streaming, where a lot of shows are now lucky to get a third season currently, let alone more.
Anything past five seasons would be brilliant. Realistically, even if it ends after 4, it’s had a good run. My gut tells me CBSAA wouldn’t want to cancel before doing five though, minimum, just because there’s a lot of damage that a perceived early cancellation of Discovery in particular could do to their image.
It’s time to accept that Trek shows are going to generally have much shorter life spans, though. Some of the concepts they are playing with just don’t really seem to lend themselves to seven season runs. For me, I just want them to take as long as they need, per show, to tell the story that they want to tell. Could be 2-3 seasons, could be 6 - whatever works.