This season is pretty weird for Manchester United. Total failure in the Premier League and going to a Europa League final at the same time.
I can assume that the players are way more motivated to fight for a European trophy and totally not motivated to put any effort in the remaining games of the English Premier League. Tottenham was also a failure in the Premier League, but a success in the Europa League. Two things come to my mind. 1.The Premier League is very competitive. 2.The English teams playing in tournaments like Europa League and Conference League are way too stronger for their European rivals. Anyway, I would put my bet on Tottenham winning EL, mostly because they are viewed as outsiders.
It turns out that in the final of the Europa League will play 15th and 17th team from EPL.
In addition, the top 3 EPL teams in the Champions League were beaten by one club - PSG, which I think will win the Champions League this year.
If it wasn't for PSG, then a team from the EPL would definitely play in the final and would probably win the Champions League, and considering that Chelsea will be another team from the EPL in the final of the Conference League, then theoretically there would be a possibility that all 3 major European trophies would be won by English teams.
So you are right when you say that the EPL is probably the strongest league in Europe right now.