Coppa Italia is already less than 64 teams. It's been 44 teams for the last few years, only a handful of Serie C teams compete.
While I'm all for reforming the Coppa and especially the size of Serie A, the biggest problem facing calcio - apart from developing new stadiums of course - is the value of the domestic media rights. The new contracts agreed last October which run for 5 years from 2024-29 are worth only EUR 900m/season compared to the 2021-24 value of EUR 927m/season (it was as high as EUR 970m/season in 2018-21). Serie A broadcasters have lost over half of their subscribers since the switch from linear television signal to internet streaming so DAZN - which is the only broadcaster to show all Serie A and B games - has only 2m subscribers (Sky (satellite) and Mediaset (digital terrestrial) used to have over 4m subscribers combined when they used to broadcast Serie A games). There is hope the new piracy shield technology which began in February can eliminate piracy services to which an estimated 5m people subscribe and increase legitimate subscriptions. This is why there is a so-called revenue-sharing element in the new contract with DAZN starting next season whereby any surplus income beyond the broadcaster's current revenue of EUR 750m/year is to be shared equally between the broadcaster and Serie A.
Jose Mourinho brought much needed eyeballs from outside of Italy. Poor business decisions. Italy also does not capitalize on marketing to the USA very well. Jose also way increased ticket sales.