PSG vs Arsenal would surely be a tough one to predict. PSG barely won over Aston Villa and Arsenal surely is playing better than Aston Villa. PSG's recent league games has mostly turned into draw or loss even though they already have a large points lead.
Among Barcelona and Inter, Barcelona should easily win it as they have one of the best European team.
Inter has been on a very low chart lately. It is unacceptable for a team that was eliminated by Bayern Munich to suffer such a defeat in the league. Unfortunately, their chances for the Champions League are decreasing. Barcelona, on the other hand, tore Real Madrid apart. I am sure Inter will have a very hard time against Barcelona. If Barcelona wins, it will be the biggest surprise of this semi-final match. In my opinion, Inter does not have much of a chance.
Just like you, currently many people are starting to underestimate Inter Milan to be able to advance to the Champions League final, especially after they were destroyed in the Coppa Italia by AC Milan and suffered two consecutive defeats in Serie A. While talking about Barcelona, it is the opposite, they actually performed very impressively this season and managed to secure 2 trophies and managed to win in every meeting with their rivals Real Madrid.
but even though at this time Inter Milan's consistency is shaky, I hope this does not affect their match against Barcelona in the Champions League Semifinals, I hope Inter Milan can provide a pretty tough fight against Barcelona, so that the match becomes interesting enough to watch.