Chelsea didn't always play well against each top team in EPL. Chelsea was defeated by Liverpool in matchday 22, Chelsea was beaten by Man United in matchday 15, and they also ever got the defeats against Newcastle and Aston Villa. This team only played well against Man City and Arsenal. So, I think we can't claim that Chelsea always played well against big teams of EPL.
It is true that the final EFL is a special match, Chelsea must have a big motivation winning the match. However, I'm not sure Chelsea can win the match if Liverpool plays with their best lineup. Sure, Liverpool should be the favorite to win the match because they have a better quality and mentality of the players.
Chelsea match statistics this season is very uncertain, sometimes they play well and sometimes they lose to average clubs. For the Carabao Cup final, I think Liverpool deserve to be favorites to win the trophy even though Jurgen Klopp can't field his best squad due to injury. Pochettino is actually also facing a storm of injuries, the difference is that Liverpool is more consistent than Chelsea when faced with a situation like the current one. Chelsea motivation to win a trophy is very big, because they don't want to end the season empty handed without any trophy, while Liverpool are currently favorites in the Premier League and Europa League.
Liverpool and Chelsea have officially announced on the club official website that several of their players have suffered injuries, and it is possible that they will miss the Carabao Cup final. Jurgen Klopp faces a bigger challenge because he has a busy match schedule in four different competitions, the Premier League, Europa League, FA Cup and Carabao Cup. Jurgen Klopp will of course try his best to balance the team in every competition, but Chelsea can take advantage of the fatigue factor of Liverpool players who have a busy match schedule.
Chelsea's performance this season has not been decisive and it could be said that it is not very consistent. It is true as you said that Chelsea sometimes play well and are surprising when facing big clubs but tend to lose when facing average clubs so it is difficult to predict the results that will occur Chelsea get in every match they face. Liverpool deserve to be favorites in the league cup final because Liverpool's performance is more promising than Chelsea, but Chelsea also won't let them lose at home and Pochettino won't let his club not win any trophies this season.
Both of them are experiencing a storm of injuries and it is up to the coach to play out his strategy to build the club and rotate players. Jurgen Kloop is smarter at rotating players, therefore currently Liverpool is still quite consistent in winning in contrast to Chelsea who are erratic.
With the many schedules facing Liverpool, it is quite difficult for the players because they may lose a lot of energy, but I hope kloop maximize the performance of the players and provide convincing motivation, the most important thing is the main competition and also the European League, the other things Liverpool can adjust to.