Pogba and Ibrahimovic both signed for United without CL football. Hes 19. Yes hes one of the hottest prospects in the world, but we arent competing with real Madrid or Barca. He wants the prem, meaning we're competing with Liverpool/City (played for one already, the other he wouldnt start in), Chelsea (a threat, but also not in great shape, and they bought Pulisic and Ziyech within the last year and a bit), and nobody else. United isnt a "nothing" option. We're a huge lure for any young english player, regardless of CL football. Players like him will look at us and think he can be the difference maker.
It's like people forget that Liverpool havent won the title for 30 years and until 2 years ago weren't competing for anything, and don't have close to our financial power, overall brand appeal and lure, etc. Yet they still signed hot prospects over the years.