Yeah, they don't have a better chassis, better tire wear, better drive out of corners as a result, faster through the rest of the lap that isn't a straight and didn't have slipstream then DRS down most of the straight.
If he had more actual power then it's because Mercedes were willing to use more laps under higher engine modes or Stroll was using more power to defend around the rest of the lap while bottas saved up some more juice to use on the main straight for a pass.
You can't say car A passes car B, therefore car A has more power. Two cars with exactly the same engine mode, exactly the same power, exactly the same tire life and exactly the same electrical usage... one can still pass the other down a straight due to slipstreaming and DRS so I have no idea what you think this video is showing.