Why is humanity looking for habitable planets instead of fixing earth?

I just don't understand why scientists want to look for habitable exoplanets that we will never be able to get too, true earth-like planets are likely thousands or millions of light years away, which is honestly a good thing cause humanity doesn't deserve the ability to go another life having planet and commiting sadistic acts towards the alien animals that could exist there, whatever is out there is very lucky that they didn't evolve alongside us and don't have to deal with our fuckery like the poor earth animals so, and those planets would still be uninhabitable for humans since they would have a different atmospheric composition, gravity, climate, plant life etc, earth is the only one we will ever be able to live on, so instead of trying to look for other planets we can molest, why won't we focus on fixing earth you know the only planet that we've specifically evolved to live on?