The Champions League has some really good teams playing each other, but that's it.
Football is so amazing because of the culture around it and you get nothing or very little of that in the Champions League. It is pretty much a football dystopia where every bit of passion
has been eliminated to be as pleasing as possible for the sponsors.
Football needs rivalries and you only find them in the leagues, although the Premier League all but eliminated football culture from the stadiums, you'll find more of that in the pubs these days.
I've been to 6 PL games in recent years and there were long stretches where there was absolute silence and the crowd behaved more like a Tennis audience.
It's a similar situation in Italy btw, the Ultras have been pretty much purged(some for valid reasons though) from the stadiums and the days where the stands were an absolute madhouse are gone. I was at the Genoa derby 10 years or so ago and didn't even bother to watch the game itself because the show in the stands was 10x more entertaining.
TLDR: I am just salty about modern football.