But you know the outcome of the war. You know that Burnham it's on a road to some kind of redemption, even if it's looking like a bumpy journey. They released the alien bug, Tilly is irrepressibly hopeful, they fought to protect alien allies, etc.It's not an argument just a matter of record. Personally I do like to feel hope for the future.
The show is no darker than TNG's borg episodes, or DS9 during its Dominion War. I think people are comparing the show to its predecessors with rose tinted spectacles. There may have been a higher proportion of hopeful episodes in those shows overall but probably because they didn't open during a war. If Discovery sees off the war, it has plenty of other places to go.
The Orville is fun but it does feel quite preachy with a USA-centric political spin. It is a welcome throwback with a modern comedic twist but I've become disappointed quite quickly at how the sexual dynamics have devolved into the traditional two male characters for every female character formula. Discovery is at least pushing the envelope in a number of ways. They're both fun in their own niche.