Why would we imagine that? We've seen the movies. We know better.
Thor was beaten bloody, off panel, at the start of Infinity War. Both Captain America and Tony were black and blue at the end of Civil War, Mysterio tore Spidey a new @$$ hole, Hulk got a beat down, and that's just off the top of my head.
MCU actors seem to understand what makes you bad ass isn't returning every punch, but getting back up every time. That, or their contracts aren't dictated by insecure action stars who can't actually do any acting :P