Is that it greatly increases your odds of seeing a pot 2 team from a much better league due to collision rules. In this case, that didn't even happen to them and despite having a pretty mediocre team (Benfica) in that group, they still sucked.
Leipzig got slotted low just because of how they finished, but ended up getting the easiest group.
4 La Liga, EPL
3 Bundesliga, Serie A
2 Ligue 1
I feel like recently there’s always been 1 wild card that advances
That no teams from outside the top 5 leagues (England, Spain, France, Italy, Germany) qualified for the knockouts.
I was cheering for several of these teams, so I did some research. And DakotaDomer, you're wrong only in that not only has there been at least one team, but there has always been TWO teams to advance. So yes, this is pretty rare, as in the past 7 years at least 2 teams outside the big 5 leagues have made it to the knockout rounds. Although this comes with serious caveats about who usually advances. Here are the past years starting from 2014 (knockout rounds happen in the spring so 2014 refers to 2013-2014 season).
2013: 4 Porto, Celtic, Shaktar, Galatasaray
2014: 3 Galatasaray, Zenit, Olympiacos
2015: 3 Porto, Basel, Shaktar
2016: 5 Zenit, Gent, Benfica, PSV, Dynamo
2017: 2 Benfica, Porto
2018: 4 Beşiktaş, Basel, Shaktar, Porto
2019: 2 Ajax, Porto
2020: 0 Suprising
You can see that in several instances they are the same teams, with a Portuguese team finding it's way past 7 times in 7 seasons, but also a Ukrainian powerhouse advances half the time. in fact, of the 23 times a non-big 5 league advanced, 16 are repeat teams, so the teams that do make it through are usually the same certain teams. In the past 7 years, that amounts to 6 semi-perennial teams, Porto, Basel, Shaktar, Galatasaray, Benfica and Zenit who have advanced at least twice.
Also, of these prior-to-advance teams, 7 of them (out of the 13 non-Big 5 group stage places) were in the group stage this year; Porto, Olympiacos, Shaktar, Genk, Benfica, Ajax and Galatasaray. However it just so happened, none of them went through. So the minnows' chances were certainly there, especially Zenit, Benfica, Ajax and Shaktar who all missed advancing by 1 point. It clearly seems like an aberration this year that not one of the 7 semi-perennial knockout round teams moved on.
I don't know if that just has to do with timing or if it is related to the amount of money made/spent by the top clubs and how that impacts coefficients and seeding/grouping. I task you with keeping up with this in future years so we can see if it is a trend.
Nothing?