All 4 teams promoted in Italy from Div II to SerieA this season are former SerieA teams. 2 of them were promoted right after relegation, 1 after 2 seasons (but last season another former SerieA team was promoted insteadl) and the last one after 5 seasons. In one case, both finalists were previously in SerieA.
In Div III, 7 teams out of 16 made their comeback to Div II from Div III.
Only one was instead able to go straight from Div IV to Div II.
All 4 teams demoted from Serie A this season are very strong and it will be very difficult for any other Div II team to compete against them.
My impression is that the distance between top divisions is (for economical reasons) too big in countries where an equilibrium has been reached.