He gets way too much credit. He's just found himself in the right place at the right time. I think his game management has been really poor and his strengths are all based around keeping the players on the same page...but that might be as much down to the fact we actually have a set of players who aren't all driven by their egos.
He is however extremely lucky...he's gotten to a semi final and a final by, with the possible exception of Germany, beating a bunch of teams you'd expect any competent manager to beat when managing England. Granted you can name a few England managers who have failed to do even that, but actually only a few. Well, just Hodgson and McClaren really.
Capello, Sven, etc. all got us to tournaments and generally went out to the likes of Brazil, Germany, Portugal etc. when they were actually very good teams. They'd all have had England in the semis of the world cup and probably in the final of this tournament if all they had to do was not lose to teams like Sweden and an exhausted Denmark...and I reckon possibly even with a better chance of winning it because they wouldn't start fecking Saka as part of a three man attack, play 8 defenders, and then leave a collection of the best young forward players in the world sitting on the bench. Or let a game drift into extra time and risk losing it before making very obvious changes.
I wouldn't be surprised if England got soundly beaten tomorrow, although I hope they don't and the home ground factor should help them...but even if they do Southgate will get a load of credit, which is weird really because he's been handed more luck and benefical circumstances than the next 50 England managers will get combined. When is the next time England will be able to get to the final of a major tournament where their toughest opponent is Scotland, during a pandemic that has disrupted every other team, where every other team has had to fly around the planet between games while England haven't, and where all except one of England's games have been in their home stadium which the away team's fans are basically banned from getting to? If we're being honest if Southgate can't win a tournament in those circumstances with an actually pretty good set of players, he is never going to win one.