The absence of crowds is probably a red herring introduced to try and explain away these crazy results without having to admit that these hitherto invincible players are actually nothing special. After all, ALL teams are playing without crowds, so that should even out. Perhaps the way to decide about crowds might be to study the Scottish lower divisions, where absence of crowds is normal at all times. I wonder if their results are noticeably different under covid, but it's too tedious to allow of analysis!
I'm not saying that the presence or absence of a crowd is responsible for Liverpool conceding 7 or Utd conceding 6 or Citeh conceding 5 or any of the other high scoring results. Last year Southampton conceded 9, and they were actually pretty good.
I just think that the crowd inducts emotion into the players, and emotion means that you make different decisions. It can influence how a player feels about taking risks. You see it all the time (most often with younger players) - as players get abuse they take fewer and fewer risks because they know what happens if they do something wrong. Playing without fear and doing what your boss has told you to do is a lot easier when 30,000 people aren't yelling at you for doing it wrong.
Put yourself in the scenario as a fan - your team is 3-0 up, pouring forward like they have all game, and get caught on the break and it's 3-1. If you are expecting to win the game, you probably think it's time to get #4. If you aren't expecting to win the game, you just want it all be be over and get to the end at 3-1. Crowds communicate that sort of thing very effectively to the players - you can hear it happen. The tension suddenly rises, and what was a cruise to victory becomes all panicy. You can also hear when teams are playing badly, the crowd will get on their back and further inhibit them - Everton are a good example of this over quite a few years.
Alternatively, look at goal celebrations - players involve fans (when they are in the stadia) when they score because of the emotion pouring down from the stands.
You can't draw a conclusion by comparing with lower league teams, because those players are used to not having (significant) crowds, and don't feed off the emotion like the top level players do.
Fundamentally for Villa (strange how we're still talking about that), I think it was an issue about the front half of the team not working in concert with the back half (and neither with the goalkeeper). The back half were playing as if they had a sweeper keeper, and pressure on the ball. The front half weren't pressing, either because they were confused as to who to press or because they weren't thinking they were supposed to press. If you're high, with a stay-at-home 'keeper and no pressure on the ball, they are going to get in behind time after time.
And that picture is astonishing. Ole called it schoolboy, but if that happened in a schoolboy game you're wondering about the coaching. Also, no fans means that Ole (+staff) should have been yelling at whichever defender was last man not to wander. And there's no pressure on the ball either.
