Finishers going back in time look worse than they were because we've advanced so far in however many years. A frog splash when RVD and Eddie Guerrero doing it, versus Kevin Owens and Seth Rollins doing it today, it's a completely different scope.
Seth's finisher sucks not because of the move, but because everyone knows Kenny Omega does it so much better, and Seth is trying to do that and he can't. The superplex-falcon arrow combination is one of the best looking things he does, but I realize it's such a long-developing maneuver that makes it hard to use as a finisher.
Alexa Bliss using a DDT in 2017 is absolutely ridiculous. The move looks fine as a good move for her, but her using it as a finisher frankly makes everyone look bad, which doesn't elevate her since it's such a standard move. Twisted Bliss/Sparkle Splash was fine, at least until she found something that was better. Kind of would like to see her use a submission, Alexa imploring someone to tap out is something that would be perfect for her.
Likewise Dean Ambrose, I never liked the Dirty Deeds, I even hate the name, too. I don't even like Bobby Roode using one as a finisher, but at least when he does it, it looks like it kills people. Otherwise, it's like if someone used a cravate as a submission.