No one can say Chelsea is a weak team. Chelsea is always a big and strong team although they are difficult playing at their best form lately.
Sure, Chelsea won't reach the current stage/round if they are a weak team. Don't forget that Chelsea is the leader of group E on the group stage. It proves that Chelsea is a strong team.
However, if we compare the squad quality and coach quality, Real Madrid is still better than Chelsea. Real Madrid also has a better experience and achievements in UCL. I never underestimate Chelsea squad, but I'm sure that Real Madrid will have a bigger chance to qualify for the next round. I even predict that Real Madrid will play in the final round.
As a Real Madrid supporter, I also never said that Chelsea was a weak team and should be underestimated in the quarter-finals. They have sacked Graham Potter which means they have made room for other coaches to do well both in the Premier League and in the quarter-finals of the Champions League. Of course we are favourites, but Chelsea cannot be underestimated for any reason.
Lampard and Ancelotti are two different coaches. Ancelotti is a coach who has a wealth of experience in the Champions League which will put a lot of advantages over him, so I think we should be the favorites even if Lampard is determined to build a fragile Chelsea.