That's annoying, I watched 1-3 of Supergirl and I never had the opportunity to watch 4. I want to, because of the actor.
I was going to ask if Black Lightning was any good, I never touched it so I've only seen him in a crossover. I guess season 1 wasn't too strong.
Season 1 wasn't exactly bad, but it wasn't good enough either. It was just okay. Season 1 felt like they were trying to emulate Static Shock to a certain degree and make it feel lighthearted like The Flash, and it had a level of cheese that didn't quite fit with the mostly serious tone it was going for.
Season 2 felt like they really hit a stride with all of the characters they established with Season 1, and then they found their own style to separate themselves from Arrowverse on top of that. They also greatly improved the tone, music, and fight scenes:
Obviously these are not daredevil level fights but the fact that they even attempted to go for something of that grounded nature shows their growth and passion for Season 2. Season 3 was alright enough and Season 4 was just ok/acceptable, but the problem was that they were mostly carried by Painkiller's actor and his tortured character arc:
The fans liked this new Mind Controlled/Trained Assassin Painkiller so much that he ended up becoming the green ranger of the show...that star cameo that show up once every few episodes and would make people tune in for a really cool action scene, but then the rest of the episodes weren't as good. The better option should have been to ensure that the rest of the episodes were written really well and he simply should have added onto that.
Season 4 of Supergirl is upsetting because it shows that if they put in the best writers on the show and put in the effort, they could have made something great with the entire show, since there's so was so much there especially when it came to Lex Luthor and Sam Witwer does a fantastic job as Agent Liberty.