The next round is just for the play off teams, teams that were positioned from 8th to 1st will be relaxing. For Lille and Aston Villa, though they had easy teams as you said, but they really tried in beating them and getting to the position at which they found themselves now. It likely that the Play offs will start in two weeks time.
You are right, teams like Lille and Aston Villa have fought quite well. This is a good challenge for them to develop better in the Champions League. But remember this is a competition that is quite stressful for any team to bring out all their abilities. And the teams in the play-offs do not mean weak teams, in fact we can say that we will see one of them in the final. For now, 8 teams can take a breath before going through a much tougher match.
from the very start, this season looks like a breakout season for Aston villa and getting this far and having to rest for the likes of real Madrid that are the defending champion and man city that are the table leaders in the league Aston villa is representing getting involved in the playoff is something remarkable they have to celebrate while hoping that when the next round starts fully, they can equally do something similar at that point. teams that are not taking part in the play of will have enough time to cool off and concentrate on league games which will help them build momentum in anticipation of the kickstart of the next phase of the champions league. even with the owners of the leagues still struggling, the potential they have to having a good comeback is still a topic that is worth discussing because as long as those teams are concerned, no one is out of the game until they have been officially knocked out.