I'll be honest. I don't watch any of the late-night talk shows, and I don't know anyone who does. The last time I regularly watched a talk show it was David Letterman - and not 'grumpy old man' Letterman, either. I'm talking about 1980's, sarcastic, angry-at-his-own-network Letterman.
Late shows used to be about access to the worlds of movies, comedy, and music - at a time when there were very few daily sources for such information. These days, if you're a fan of pop culture, online outlets have demolished the need for couch interviews. It's an archaic format that serves no purpose in a world where the internet delivers a constant stream of insightful, highly-focused, entertainment news. ...And that stream is running 24/7 so, by the time a late show tapes, the topics are at least a day out of date.
