I think the definition changes overtime. But the swoop in and save the good guy from the bad guy is more difficult now simply because it’s actually really hard to determine who the “bad guy” is.
Context is everything. Maybe you stumble upon a fight, see someone wailing on a guy pinned to the ground. You jump in, knock out the guy on top, only to realize the guy pinned down started the whole thing and the guy you just hit was the initial victim. Next thing you know, you’re getting imprisoned or sued because you assaulted someone wrongfully.
Speaking of getting sued, most liability and protective measures that organizations put in place are to protect themselves from getting sued. In a world where people manipulate the justice system to get a handout, it makes it even harder to step in and be a hero, for fear that the person being saved might have some ground to sue you.