Network TV viewership has been in decline for years and won’t plateau for a few more. And Leno and Letterman are old. NBC should have stuck with Conan, but in the long run it wouldn’t make much difference - late night talk shows on network TV were a 20th century phenomenon.
I use to watch Leno, but now I just turn on Netflix/Roku and watch Dana Scully and Muldur..
The X-Files....
They have all the 200 episodes...