Leverkusen yes, but I don't see Roma being on the same level. In my opinion Roma is not even close. They improved their game lately, but there is still a huge gap when you compare them to Liverpool. But I think we will get to see a nice test when Liverpool now plays against Manchester City. That's the toughest test a team can have.
However, I think in a final everything is possible. If Roma can manage to make it into the final, then I wouldn't assume that they are without chances. Playing a final is always different from playing league games.
In the European League, some teams can show different performances than in their domestic league, that's why we see surprises more often in this competition. I agree with you, even though Roma have experienced an increase in performance, they are not yet on par with Leverkusen and Liverpool, even though they were finalists last season and are now starting to appear impressive.
Liverpool are in a safe position to continue the second leg match, because their margin of victory is quite large, while Leverkusen have to try a little harder to win after being held to a draw by Qarabag. These two teams deserve to be favorites, and Liverpool will again shift their focus to the Bigmatch against Man City in the EPL.
On the other hand, I still hope Milan can do something impressive in the Europa League, even though we know they are not as consistent as Liverpool or Leverkusen. At least the European League will become more fierce if Milan becomes one of the teams challenging for the title. Even though he is also in a safe position, Pioli must be able to improve his fleet defense so that they don't concede easily in the next match.
There are 4 possible clubs that could be candidates for the UEL title, Liverpool, Leverkusen, Milan and Roma, of these 4 clubs it is still an interesting discussion because these 4 clubs both have very clear advantages Liverpool has quite stable strength and Leverkusen with unbeatable strength but there are still obstacles that could provide surprises beyond our expectations, namely Milan and Roma who can always provide surprises in the final round because currently these 4 clubs still have a big chance.
Except maybe when we enter the quarter-finals we will see very difficult competition and we will know which club will be the title holders because in the quarter-finals we will be able to see how all the clubs that have qualified will perform and can determine whether Liverpool or Leverkusen will still look impressive.
Something I'm thinking about right now is just a surprise like Sevilla will be repeated Milan or Roma because slowly without us realizing Milan and Roma have quite big potential.