And what more could he do at United? Because you ain't toppling City in the league anytime soon and you're light years from being able to win the CL.
The notion that United have "all the tickets to win this prize and win it soon" is a non-starter. You've regressed into being merely a top 6 club and it will take years to turn that around.
I get your point but there's a difference between being a top-6 team and a top-6 club. Results along these years speak by themselves, but even in our current situation as a club there's no comparison between United and Spurs.
I'm always respectful about Tottenham because they're doing pretty well, and from the outside you look like a serious club that know what they do. But the truth is you can't go and break a world transfer record for a player like we did with Pogba, and even if you could somehow I don't see Levy doing it. Nor giving outrageus wages to someone like we did with Alexis, fighting for him face to face with City.
We've done bad decisions and money hasn't been spent wisely, but the financial muscle and the ambitions as a club remain there. I don't expect us to fight for the league and CL next season (regardless of the manager) but I can see us finally getting closer every year if we start working in the right direction as a club. And it means having football professionals taking decisions and planning our future, and also a proper modern coach who can get more from the squad.
The 'top-6 club' as you call us was 2nd in the league last season, while playing one of the most underwhelming and uninspiring football that I've ever seen. Discontent players, outdated miserable manager and transfers not impressing enough. Imagine what we could do if we start doing things in the right way, spending big in the right players and introducing them in a working system.
The possibilities of Pochettino will be always higher in the middle-long term at a club like United than at Spurs, and I don't mean to be arrogant, it's pure logic after all. If we offer him the chance of coming and he doesn't take it, then nobody knows when another train will come again. He's exposed to losing credit if results are not good enough in the following years, and some other people become more attractive.
Football is unpredictable and many things can happen, but all things considered and after 5 seasons there, I think it's the right moment for him to leave Tottenham and face a bigger challenge, and I'm sure that he feels this way. If I'm wrong we'll discover pretty soon.