BBC shows often only have 6 episodes. There it has to do with one or two writers typically writing every single episode themselves (which takes time) as opposed to the American way of doing things which means TEAMS of script writers (which on the down side leads to less consistency and some might say possibly quality per episode). Of course, each episode might take more money and/or time to produce these days with all the special effects, etc. they put into things, so they sometimes limit things to see how it will do or to keep the quality level up (theoretically at least). I know Gillian Anderson quit the new X-Files precisely because she doesn't need the money anymore and the filming schedule was too long for her at her current age and financial level of well-being (away from family too long, etc.). Less episodes might have meant it stuck around longer. I guess we'll never know. It was never going to be as good as the original shows anyway. They run out of ideas sooner or later, like most shows.
For example, Red Dwarf sucks compared to earlier seasons, IMO, for example. They should have continued the Season 7 idea as that opened endless new doors for comedic opportunties with a full crew in deep space, but no, the fans HATED the idea just bdcuase it changed the original premise of Dave Lister being along in deep space (even though the ship rna into NOTHING the first 3 million years and all the sudden 3 MILLION LIGHT YEARS AWAY (according to a script that said that), there's all these human-made "Gelfs" etc. 3 MILLION light years??? That would be many GALAXIES AWAY. Did Holly never think to make the ship go in a circle or call or help from a decontamination crew or something before flying in a straight line for 3 MILLION years??? How is the food not bad? How is the ship still there? It was absurd from the start so changing the dynamic shouldn't have mattered, IMO. All that mattered was whether the show and characters were funny and clearly a Rimmer that can touch or is alive is capable of more comedy types than one that cannot. But people hated it anyway. Now the new show is boring as watching paint dry, for the most part. No explanation for the cliff hanger of season 8. Nothing. The ship doesn't even remotely look the same either (they used to at least 'try'). Ah well. Nothing good lasts forever (and yet Picard is back anyway).