Interestingly in recent years no team have consistently won the Europa several times in a row, the fact that the Europa keeps coming with surprises especially with who turns out to be the champions is one thing that keeps it really lively and interesting, the Europa is now even more competitive then some of the domestic leagues in Europe, defeating Liverpool and Leverkusen by Atlanta happens to be one of the highlights of the champions league last season.
It is true. In the last 8 seasons, there is no team winning the trophy in a row. Although Sevilla still becomes the most team to win the trophy, but they never win the trophy in a row. After winning Europa league trophies 3 times in a row in 2014 - 2016, no teams can win it again in a row. It indicates the strength of the teams in Europa league is quite equal recently. There is no superior teams anymore, the winner in each season may be a different team. I think Europa league becomes more interesting and competitive.