It's very realistic for Liverpool to be favored as one of the strong candidates to win this season Champions League, as they have all the attributes needed to win it. Arne Slot has a squad with balanced depth that is quite ideal for a trophy contending team. What they might need is a bit of luck to have a smoother journey than last season.
Speaking of the defense, every team can actually develop to be more solid in the future. Overall, every player in the main squad must be in their best form to be able to win the trophy, this applies to all contestants. The situation can change drastically if a key player gets injured. Last season, PSG was lucky to avoid serious injury problems, and all of their players were in the best condition.
Last season many people thought same especially when the finished the group stages unbeaten but at the end they couldn't even get past Round 16. Liverpool again, might just be good in their league and still become toothless in the Champions League especially after the the group stages. I'm just saying so we don't expect so much from them in the UCL. This competition has a way of humbling trans that people think they are going to win it.