PSG is a good team and they're playing really well. But when we look at who Inter faced compared to PSG in the semifinals, we can definitely say that Inter should never be underestimated. They managed to knock out Barcelona, who might currently be in their best form.
Who you knocked out in the Semifinal does not matter when you get on the pitch for the final, all of that is gone, mind you that there are no easy teams in the knockout stage of the CL, so any team that gets to the final deserves it. That said, i think Inter have the slight edge, they are a very solid team, same as PSG, but i think right now Inter are slightly the stronger of the two teams, it would still be decided by fine details, but we'll see.