I don’t think PSG is a weak club compared to Liverpool. Football is unpredictable and while Liverpool may be considered favourite in the match against PSG, I wouldn’t underestimate PSG, they are champions in their domestic league and are capable of competing against other top teams in Europe.
PSG History at UCL
In 2023/2024 they reached the semifinals and lost to Dortmund. Not underestimating PSG, but against Liverpool I doubt they can win. Maybe there is not a big chance that PSG can qualify for the next phase, I prefer Liverpool. But PSG's development is indeed quite good, even though their best achievement is only the semifinals. They are always beaten by big clubs from the EPL, La Liga, and finally the 23/24 season from the Bundesliga. This year in the last 16 they also competed with a perfect points team during the new UCL format. So I squeeze PSG has a strong opponent.
Source : https://www.reddit.com/r/psg/comments/11rlqi6/psg_have_only_been_eliminated_by_big_clubs_in_the/?rdt=52324
That is a great summary. With the money they invested and the big names they signed, these results are a disappointment and in the Ligue 1 thread here some people claim that the league is competitive. But I think the biggest problem is that it is not competitive and PSG can't handle the jump in required performance when they play their relaxed trainings against French clubs and then immediately need to switch and play the best clubs in the world. It's not helping them to be that dominant in the domestic league and yet you can see that there are some pros here who say Ligue 1 is competitive lol.
My bet is that they won't win the Champions League for a very long time unless they get tougher competition and are put to the test very frequently.