If anything, I’d say the acting isn’t as good in SG1 and Atlantis as DS9. I think the reason SG1 works is the same reason the MCU (Marvel Cinematic Universe) is

If anything, I’d say the acting isn’t as good in SG1 and Atlantis as DS9. I think the reason SG1 works is the same reason the MCU (Marvel Cinematic Universe) is more popular than X-Men or DC movies: MCU doesn’t take itself seriously. When you have plots that are, at times, a little silly (as SciFi often can be) you need a suspension of disbelief to enjoy the show. When stories are too dark or take themselves too seriously it leaves the audience taking the story seriously. And that can be a problem if any aspects are far fetched or hard to take seriously. However MCU doesn’t take itself seriously (generally speaking). It pokes fun at itself and winks to the audience at times saying “we know this is daft too but let’s have some fun”. This makes it much easier to suspect one’s disbelief. SG1 employs the same approach to storytelling where it will use humour to disarm some of the more far fetched sub-plots allowing the audience to play along more easily.