If things can always get worse then the corollary is that things can always get better too
Maybe when the horrible people see that a horrible person just melted away into nothingness after some rando snapped their fingers they might change their tune
If you are talking about nation state leaders, I'm struggling to think of one where they don't just end up getting replaced with someone similar - Putin turning to magic dust doesn't suddenly dismantle the structure that allows for a dictator, so another dictator will slide into the void. Same with Trump - American politics doesn't stop being insane just cos he's not around, and now that people know/think that a politician of his style can win, there will be a queue to cynical imitators ready to go.
I'm less familiar with Indian politics, but I don't think the BJP suddenly loses its power if Modi disappeared. Israel will still have it's hard right nationalist core without Netanyahu. North Korea will find another Kim.
I guess my thesis is "focus on systems, not people"