I think Southgate is probably shutting his critics up on basis of results. One can say that they have all the attacking talent, however, their defence is the weakness and to win international tournos you need to be able to hide your weakness more than show off your strength.
His decisions are ballsy - Grealish off for Trippier could have backfired just like numerous decisions of his this tournament, but he's getting results out from the team and one can't question him as long as he's ticking the most important box.
Lastly, the game management in last 7-8 mins was excellent. Kept the ball, kept moving it from side to side and killed the game off. Top quality management right there