I have some level of trust in Manchester United to defeat Barcelona and knock them out of the Europa league. Manchester United have a history of playing very well against toughest of opponents just as they defeated PSG on several occasions and so far the only team to defeat Arsenal this season in the premier league, same way they will up their game against Barcelona and get the expected result in the game. Barcelona have a star studded squad but it definitely won't be easy competing against Manchester United.
Yes, I agree with you, MU will be strong and powerful if meets a level 1 team like Barcelona and PSG. When we look at how they defeated Bournemouth 3-0 earlier, we do not doubt that they will be easy to overcome Barcelona. But, they are still being watched, especially after Ronaldo leave, because their habit also with lost still doubt repeated any time, and any match. So, I still don't know how Ten Hag managed the squad to be compact and unified without Ronaldo, seem to look like happy, and play loose.