I honestly can't think of another English coach who would have bettered or achieved the same as Southgate over the period of his tenure.
He suits international football and the associated part-time coaching role perfectly.
England have won nothing since 1966, and we were somewhat fortunate then. We've been largely anonymous at tournaments over the succeeding years other than a couple of close things.
As you say, it's an impossible job. Anyone who genuinely expects England to win a senior tournament is dreaming. Like him or not, compared to his predecessors, Southgate has done well.