The teams from Laliga performed quite impressively in the Champions League where 4 representatives from Laliga were able to end the last match in the group phase as group winners such as Real Madrid who led Group C, Atletico Madrid who led Group E, Real Sociedad who led D and Barcelona who led Group H. It seems that if you look at the strength of these 4 teams, I think they will succeed in bringing the UCL title home to Laliga because they have the most representatives who have qualified for the round of 16. And maybe only Sevilla failed to advance because they weren't very strong this season.
Serie A shown some signals of their return in Europe since the past season with three clubs joined three final matches from Champions League to Europa League and Conference League. This season can be their continuation of this but we will have to wait for clubs from Serie A in Europa League and Conference League.
La Liga, no doubt that they are a very strong league and with Real Madrid, Barcelona, Atletico Madrid, they are strong enough to move next. Real Sociedad did their matches well in group E too. Together they made an excellent group stage in Champions League for La Liga club. When going further, Socidedad might have more problems with their lack of experience in Champions League but I believe other three clubs can play well.
Apart from that, of the Serie A representatives, only AC Milan failed to advance to the round of 16 because they lost in goal productivity to PSG. Of the Premier League representatives, only Arsenal and Manchester City qualified, while Manchester United and Newcastle United failed to advance to the next round. From the Bundesliga, only Union Berlin failed to advance. I think this is quite an interesting season for the defending champions, namely Manchester City, because they have opponents who are tough enough to stop them from winning the title.
Manchester United and Newcastle United ended their group at a fourth position and they even will have to completely return to Premier League, no Europa League to play after Champions League. The ending of Newcastle United was expected because it is a first time they play in Champions League after many years and their group is toughest one in this season. However the performance of Newcastle United is very impressive and they create a lot of challenge to PSG, AC Milan and Dortmund.
Oppositely with Newcastle United, the performance of Manchester United is very terrible and unexpected when their group starts. Because in theory, they are stronger than both Galatasaray and Copenhagen but at the group ending, they ended with a bottom position, under those clubs.