Manchester United have been playing well when it comes to Europa League, despite some poor performances they showed against Lyon, nearly Lyon would have qualified instead of Manchester United, as they had a standing red card. The final will be tough on both teams as their performance isn't worth to talk about, you can't find either Manchester United or Tottenham among top 15th teams in Premier League standing, qualifying to play in the Europa League final is just a wonder and in a way shows that other teams there are even worse.
Everyone saying Manchester United to win should know what Tottenham are facing with fewer or no trophies for so long.
That's the reason why people saying Manchester United will win, Tottenham will enjoy without trophy as usual.

I see that Athletic Bilbao aren't under perform, they can still beat Getafe and Deportivo Alaves. I know those two teams are weak, but under perform team could lose against weak teams.
Manchester United can win both leg against the strongest team in Europa League, that's proving why Manchester United is the favorite.
It's undeniable that Manchester United is indeed more deserving of being favored in the final match against Tottenham, they remain undefeated so far. Beating Athletic Bilbao looks easier than beating Lyon, the final will be a completely different affair. Tottenham still cannot be underestimated, even though their reputation in European competitions isn't particularly strong.
Regardless of all that, there are reports stating that the club will not hold a celebratory welcome parade with a bus if Manchester United emerges as the champion. Furthermore, it's reported that Ruben Amorim will pay for 30 tickets for staff members out of his own pocket to watch the final, due to the budget efficiency policy currently being implemented by Sir Jim Ratcliffe.