It won't be remembered and it won't matter to most people, including Jack himself ( probably ), but it's a symptom, one of many. Throughout the tournament Southgate didn't know his best 11, or his best 14, or his best formation. His tactical approach has been incredibly one dimensional, lacking in imagination and playing down to the opposition level, instead of taking the games by the horns and using the incredible talent he's had at his disposal. This England team was the best in terms of ability and talent in the tournament, honestly it wasn't even close. I watched the Brazil and Argentina final as well - they're both significantly worse than this English team is, or could be more like. They're being dragged down by a manager who's incapable of developing them and turning them into the force they could be.
I'm not english, so I don't really care about that team, apart from when Villa players are participating, but I really believe they can win multiple major trophies with the players they have. Southgate has done well to get them to the final, but playing the way they do is not how you should approach the game when you have the talent disparity in your favour. It's like Bruce taking Villa to the final against Filham and approaching the game in a similar fashion. Sure he's done well to get there, but you could be much more developed with someone who can take advantage of the immense talent at hand. You can play defensively and limp to 1-0 wins against significantly weaker opponents, you can call it results business and so on, but you're not even trying to reach that next level everyone knows you're capable of. Again - not even trying - this is such a waste.