I agree that we just need to do things more quickly.I don't think the style of system has become outdated nor that coaches have worked out how to counter it. We are just really shit at playing that way. It used to be one of two touch pass and move football, with incredible intensity off the ball. If a team did defend against it, they would usually run out of steam and we would find the goal we needed.
We didn't do enough to bring the next top players through to evolve it and through a combination of mother time and injuries were left with no energy to break teams down. Walking football won't win anything. Inject some pace into a possession dominant approach and it will be as successful as it always has been.
Against Spurs was the same old issues of individual errors and a real lack of energy off the ball. The latter being something Pep would never have stood for.
I do think that the league has become much more defensive, and the level of coaching is superior.
It's a bit chicken and egg, but I think we can counter point 2 with point 1.