I'm not familiar with any of the '70s shows you mentioned, although obviously I've heard of them.
I'm not familiar with Space 1999 or Lost in Space either, but they're probably better comparisons.
Battlestar Galactica had phenomenal special effects for TV in 1978, but they recycled alot of the same shots over and over during the battles.
They leave the ship on most Star Trek episodes and the sets that they canibalized from other programs are more varied than that. 70s Doctor who did have more varied and creative alien planets but they also look cheaper to me much of the time, even if they're more inspired. In general the BBC was much lower budget than American TV. I also think that alot of the "cheap" look probably comes from everything being shot on video tape. It affects the texture of everything.
Also, Pertwee/Baker era DW wasn't contemporary to Star Trek, Troughton was.