CBS’ decision to cut ties with Stephen Colbert and its decades-old “Late Show” franchise come next May will leave a major hole in the format — but one that has been widening. TV networks have been cutting costs at their late-night mainstays for the past few years.

W hen CBS embarked on the project of replacing David Letterman as the host of The Late Show, in 2014, the network spared no expense. It hired Stephen Colbert, who had collected Emmys and acclaim while hosting his Comedy Central talk show,

TV’s ongoing problems with late night have come for Stephen Colbert, with CBS announcing Thursday that it plans to end his “Late Show” after the next TV season, citing a “financial decision.” The maneuver — which ends years of original late-night programming at CBS that started when the network lured David Letterman from NBC in