Superman has had plenty of movies and TV series, and there has been interest in Lois Lane as a lead for awhile.
Greg Rucka recently teased that he's closer than ever to writing his long dreamed for Lois Lane comic book series. She already had a trilogy of successful young adult novels that focused on investigating wrongdoing in Metropolis as a teenager with a young Lex's and Clark's help. She's also going to be heavily featured in the best selling and mega successful DC Super Hero Girls next month.
During Smallville, instead of Clark being everyone's favorite, characters like Chloe Sullivan (young journalist), Lex Luthor (evolution to evil), and Lois Lane (developing journalist) were often far more popular than Clark himself. Currently, one of the most beloved aspects of Supergirl is the friendship between Kara and Lena Luthor and the drama of whether Lena will follow in her family's evil footsteps. Before Gotham, people had some of the same concerns, but then they watched the show, and it's succeeded because of the overall world created, including compelling supporting characters and engaging plots.
Get outside a place like this and to more female-oriented spaces, and you'll find there is plenty of enthusiasm for this type of program. It has a lot of potential, and it doesn't negate Superman's presence in the slightest. He guest stars occasionally on Supergirl, and he will continue to have a presence in the DCEU even if it's not right away. Superman will be fine, and people who want to see him have been spoiled for years with Clark-centric TV series and films that have happened almost unabated for nearly 80 years. His brand, if the shows are good, will only be strengthened by these programs.