My dad (early 60s, retired) moved in with my grandma (mid 80s) about two years ago. Up to that point, she lived alone, but really was getting to the point where she needed help. It's only gotten moreso with time.
He's been a saint helping her like that, but it's gotten to be a lot of work. He's more than willing to shoulder it, but be aware of what you're potentially signing yourself up for. Without his help, she'd either need to have full-time live-in help, or need to move to a nursing home, and she wants nothing to do with either option ("I don't want strangers in the house." is very heartbreaking to hear from her). He definitely doesn't want to leave, but he's aware that he's "stuck" one way or another.
I consider what he's doing to be badass, but not in any financial context.