Lois & Clark: The New Adventures of Superman debuted in 1993, making Dean Cain the Man of Steel for young millennials. The show focused on the relationship between Lois Lane & Clark Kent over more traditional superhero tales, and was endearing even if it was light on the high stakes action found in the comics.
The Flash had the more serious sci-fi action material usually reserved for the movies when it launched in 2014. Real supervillians, real danger, and that epic "fate of the Multiverse is on the line" quality that Lois & Clark lacked.
Fastforward five years.
Barry Allen is fading from existence. Not due to a temporal paradox, but rather the result of a series unsure of what else to do with him after 5 years. His role on the show has changed from the protagonist into something more like a host. He opens the show, welcomes new characters, and gives them guidance...but it is their story. This year it is Nora, last year it was Ralph. They are the Skywalkers to Allen's Obi-Wan. The show needs to reinvigorate Barry Allen, and the tips for doing so can be found in Metropolis of the 1990s.
The Flash has surpassed Lois & Clark in many ways, however, Lois & Clark excelled in ways which The Flash is struggling with.