Ok, no one's saying pull off Mou vs Pool (0-0). All I'm saying is these teams can atleast try to play a bit more cautiously- say something like Palace vs top teams.
As far as the dominance bit is concerned - teams might have more possession, but lesser clear cut chances if you play slightly deeper. Think about it this way - an underdog is more likely to win 1-0 against Bayern than win 4-3. And if you play a high line, top teams will score 2-3 goals past you unless they have an off day.
Like today- Leverkusen got a 1-0 lead vs Bayern. Irrespective of Leverkusen's results against top sides, Bayern are on an incredible run of form. If you get a lead against them, common sense dictates that you should sit back a bit rather than having 8-9 players in opposition half even when Bayern have the ball. Add to that, Bayern had Gnabry and Coman on the pitch along with Davies. Its basic understanding that a ball over the top will more likely than not mean that you're giving up a big chance against them and that's what happened. Bayer got punished for being too daring and not taking opposition and their strengths into account