Liverpool is one of the challengers in the Europa League next season, the player material that Liverpool has will place it as the superior team in this competition. The failure of this season will soon be evaluated, Liverpool will increase its strength to provide competition in the EPL and UEL. Next season Sevilla will not be in the EUL unless they get knocked out of the UCL group stage in third place. Surprises can still happen next season if the big teams that were knocked out of the UCL can stay in the UEL. Liverpool is one of the teams that is considered to be able to provide competition to other teams, but as we know, in football there are always surprises that happen beyond predictions.
I can't remember the last time Liverpool won the Europa League title, but next season they are strong candidates to win it. Liverpool clearly have better player material than some of the other European League participants, but I also don't rule out the different possibility of several teams being declared to have joined the Europa League after failing from the Champions League group stages. Sevilla is one such example and they won the Europa League title this season although Barcelona, Manchester United, Arsenal and also Juventus are the favourites.
So I can only say that even if Liverpool are a strong team, they won't get any guarantees about the title. Every team will fight for the title, and whoever is able to win it will be the best in the season.