Yes, the gap between Milan and Juventus is quite a lot from the teams at the top. It's just that for Serie A, the competition is very tight.
Indeed very tight as most of the top teams win their games nonstop or at least they don't lose them. Lazio has been doing amazing and so has Atalanta, Inter and Fiorentia, which is probably the biggest surprise of them all as I rather saw them further down the table. Although Roma played quite well, i don't say they played well, but only quite, Ok!. They played a bit better than what they did under Juric, but there are still many loopholes in their defensive line.
Even Claudio Ranieri admitted it, he has tried to implement his strategy and change the game in the second-half time. But, there is a lot of work to do and to fix in the club. He is aware of that and it will not be easy to change it so quickly in his game.
Source: Claudio Ranieri