Stephen Colbert hosted his fellow late-night frontmen Jimmy Fallon , Jimmy Kimmel , Seth Meyers and John Oliver on Monday’s episode of “ The Late Show .” The meeting of the minds was a send-off for Colbert as he enters his final days as the face of “The Late Show,” which goes off the air for good on May 21. Partway through the joint interview, Colbert prompted his guests to “make a case for late-night,” given that the genre has struggled in recent years. Kimmel was the first to go. He emphasized the strength of late-night’s fanbase, which he experienced firsthand when “Jimmy Kimmel Live!” was briefly suspended . “We have a lot of shows. 30,000 people watching each one, and it adds up,” Kimmel said. “People watch us on YouTube now. People have a lot of different options and they keep coming to us. I will tell you, when I got knocked off the air for a few days, people canceled Disney+. Why aren’t people canceling Paramount+?…