There's more to it than that. As every decent footy fan knows, Kane has never won anything of note, and that's for a good reason. Kane is too slow to be effective against the better teams, but against the rest, when the defence drops deep and he has time and space, he's lethal. Spain were never going to give him that, so playing him was literally a waste of space and time, and that's therefore entirely Southgate's fault. That we scored after he was subbed is not an accident, because Watkins forced their defence to drop deeper, allowing for more space behind EDIT: in front of them, that Palmer took advantage of. WHICH IS EXACTLY WHAT WE NEEDED FROM THE START. But for us to then decide to sit back and let Spain beat us after we scored is also on Southgate.
The team we had at the end (with or without Toney) could have won us this match from the start, but Southgate alone ensured that wasn't going to happen.
He's not good enough to manage the players we have, and anyone who doesn't think this doesn't want us to win anything...