I will refrain to comment on the quality of politicians of either country, present, past or future, since that could stir emotions that generally ends up with the deletion of a forum thread. But I'm a number guy, so let's look at the data.
As of Sept 2024 in Florence there are less than 13,000 short term rentals active online (of which less than 10,000 full apartments rather than just rooms). The highest concentration per resident in Italy.
As of 2022 there were 525,000 housing units in the province, out of 455,000 households. In the City of Florence there were almost 185,000 housing units. Short term rentals are therefore less than 8% of the total in the City alone, although mostly concentrated in the historical center. Approximately 30% of the housing units in the historical center of Florence are rented to tourists as short term rentals.
Almost 10,000 houses in the city are also kept empty, according to several Florence newspapers, presumably owners are afraid to rent them given the incredible protection from eviction that tenants enjoy in Italy. I was one of those owners. Basically if a tenant stops paying rent it takes from 6 to 9 months to evict the tenant, and thousands in legal costs. If there is a minor in the housing unit you are renting it is virtually impossible to have the tenant evicted, even if the tenant stops paying rent, so the only option is bribe the tenant to leave with thousand of euros of "gifted" money. If you want to evict a tenant for reasons other than the fact the tenant is not paying, it is also very difficult to have your house back in reasonable times.
Many Florentines also abandoned the historical center (including some of my friends, who are now AirBnB hosts with their ancestral apartment where they grew up) simply because it is inconvenient for todays' needs that people have, especially for families. I'm sure most of you enjoy the possibility to park your car in front of your house to download your groceries, to have a garage for your car, or to go to the upper floors of your apartments using an elevator. Some of you may also enjoy the possibility to remodel and expand your house. Those options are often off limits in the historical center of Florence (or most historical centers) where it is next to impossible to drive a car, have a garage, or do any remodeling in the exterior of your house. So most Italian families prefer to stay outside the historical centers and rent the place to tourists or students (both of which are likely to leave in a short time and present little risk of difficult eviction), or to singles (often immigrants) with no (unevictable) minors.
It is true that short term rentals may have the effect to increase average long term rents in the historical centers, but I think the biggest issue is that AirBnB also has the effect of reducing the average price of hotel rooms, and that goes against the interest of hotel chains, hotel owners, and Federalberghi (the Italian hotel association and lobbying group). According to a study aby the National Bureau of Economic Research, AirBnB resulted in a direct benefit for consumers of about $40 a night in lower hotel costs. The University of Michigan has determined that an increase of 10% of AirBnB offerings results in a 4% decrease in hotel revenue.
Hotels don't like competition from AirBnB the same way that taxicabs don't like competition from Uber. The taxi lobby was able to have Uber basically banned in Italy. Now the hotel lobby is trying to do the same with AirBnB. The fearmongering nonsense about "over-tourism" is part of the strategy employed by the lobbying interest groups. In the end it's all about money and greed. It wasn't AirBnB that created the overcrowding of the Cinque Terre, it was online and media exposure, increased average income of people around the world and therefore ability to travel, and the new cruise ship dock at La Spezia.