When it first was founded by Ted Turner TBS was like TNT and became a variety channel but from the 2000's TBS was starting to change their image and become a sitcom channel and show comedy movies and why I think caused them to do this was getting a fresh audience because before focusing on sitcoms you could see sports like NASCAR racing movies dramas and cartoons for kids but once they changed direction and focused on sitcoms TBS knew that sitcoms did well to attract viewers. Another thing that made TBS well known is that they would do marathons of sitcoms like Last Man Standing and others and they knew that with the sitcom format it worked. What could work for TBS is on holidays have special marathons like on Halloween show The Munsters and Bewitched and on Christmas add the Rankin-Bass Christmas specials and the original Miracle On 34th Street in addition to the marathon of A Christmas Story and it would be a good idea

Sadly, variety channels like TNT, TBS, USA, etc became unpopular. Sitcoms and the like are what the masses want(ed) to watch, so those channels switched gears in order to survive. It's the same reason many channels just do "binge" blocks of one show nowadays, because people like "binging" stuff. Trends change, so companies try to change with them.

FYI, I loved those variety channels from the early 90s, and I miss them.