Because it’s football and it’s a cup competition.
If the best team and manager meant you’d win the trophy then Man City should be winning the Champions League on a regular basis ?
So many get wrapped up and obsess over the Manager, the players, the formations, the tactics , the subs etc and yes they do make a huge difference but people forget that football is just a sport … only takes a couple players to have an off day , a bad ref/var decision, red card, hit the woodwork, missing clear chances or other bad luck and that’s it. Your out. So many fine margins. England lose on a penalty shoot out in a cup final and it’s ’we will never win anything with this fraud in charge’ the next day- laughable considering we got to a final only to lose a 50/50 shoot out.
I could never confidently think England nor any country will win it.