I see the crew of the Discovery wearing Disco t-shirts, and the crew of the Cerritos wearing Ritos t-shirts, but I don't see the crews of the TOS Enterprise, TNG Enterprise, Deep Space Nine/Defiant, Voyager, NX-01, Stargazer, Dauntless or Titan wearing t-shirts. Clearly this is proof that DSC and LDS take place in their own universe.
Oh, I have a simple explanation for that!
We just aren’t following any characters with that much panache, fashion-forward, love-my-ship swag into their off hours on TOS Enterprise, TNG Enterprise, Deep Space Nine/Defiant, Voyager, NX-01, Stargazer, Dauntless or the Titan. They’re out there though, who wouldn’t want a fun, cool t-shirt like that? 

