I think there are not many teams that are rich in any league. Most of the teams are in debt although I don't know how bad it is in Italy relative to other leagues, but Barcelona and Madrid are also said to have huge debt. Those teams who have big investors don't suffer from those issues. But I often wonder how these clubs always survive their financial problems. I have never seen a club go broke so far in one of the top leagues.
I frequently ever hear anything about Seria. In contrast to Barcelona, a Spanish league club. I believe the blaugrana are to blame for their own difficulties, as they violated FFP guidelines by signing players for exceeding the expected budget generated and offered by the club. The same scenario happened to Chelsea several years ago, and they were banned from signing players for an unknown length of time. Clubs cannot go bankrupt because they have high businesspeople who have invested significantly in a club, a single individual can own a club and shares, and he can build the club despite the imposed responsibilities and debts.