I disagree. If nobody cared for it, nobody would’ve watched it. People were watching arrow and would’ve still been watching if the lead actor hadn’t quit. He decided he had enough. The same thing is true with Supergirl. Batwoman was doing well up until the point where Ruby Rose quit and they had to put in a new lead for the show. She was not really well received. Superman and Lois was actually doing pretty good, but when the CW was sold and bought by a new owner, they started winding down the shows otherwise we could still potentially have an Arrowverse.

it is true that the Black Lightning tv show started out in a separate universe, but it was folded into Arrowverse Earth-Prime at the end of the televised version of Crisis On Infinite Earths. This means it existed alongside Arrow, Flash, Legends of Tomorrow and Supergirl on the same earth.

First off if he took Barry Allen‘s power, he would be the second fastest hero in DC continuity as Wally West is faster. If you’re gonna report on stuff, you need to be more accurate. At present time Wally West on earth prime or earth one is the fastest speedster in the DC comic book universe