I took a slow zoom and my mirrorless to a birthday party at a local kids' gym not knowing the light situation. It was dimly lit, and needless to say, the slow zoom + high shutter speed to freeze motion (at least 1/160 and often higher) required very high ISO, which my camera is not good at. I really wished I had enough money to buy a fast telephoto prime for a moment.
But then, there was the saving grace of this consumer mirrorless camera: the video! I don't take videos often, but one thing I knew was that the optimal shutter speed was 2 x the FPS of the video. My camera's video mode was set at 25FPS, which meant I could use 1/60 (since there is no 1/50 on my camera.) At 1/60, the camera didn't need to boost the ISO to over 800 that it needed for 1/160 or 1/250 for still. When I checked the results back home, they were not bad. Between the grainy ISO 1600 still and the video, the video had better quality and better capture of the fun of the day.
I understand that photo and video are not substitutes; they are complements. But if you can get better video under the given low light situation than photo, why not shoot video instead? I did some google search afterward, and haven't found any advice along these lines. I wonder why.