It is quite difficult to adequately assess the chances of a team and put a normal odds when the opponent is a team that has never lost and is now entering its last match of the season. So I'm not surprised by these odds, although like many people I believed in Liverkusen's victory. They have come a long way anyway and left behind broken records, so they can be proud of themselves
Leverkusen's defeat at the end of the Europa League competition is something that should be said to be normal because Leverkusen has struggled quite extraordinary throughout this season in the Europa League. Moreover, Leverkusen's record in its own domestic league is also quite good this season so losing in the final match should not be considered a bad achievement for Leverkusen. So it is still quite natural for fans and Leverkusen itself to feel proud of what Leverkusen has achieved this season.