Accepting yourself or others as they are is important for well-being…yours and theirs.
As the saying goes, “give me the serenity to accept things I cannot change”. This is step one. If it’s someone else’s “stuff”, you cannot directly change the current situation. If it’s your “stuff”, you still can’t change the now.
This doesn’t mean you shouldn’t not work to get better (double negative noted).
Working to be different in the future is not the opposite of acceptance.