Unless you count the historical city center of Venice as a big city I doubt you'd get many big cities getting even close to those numbers
I can't easily/quickly find some numbers but if we want to accept, with a grain of salt, Gemini research on this even in Venice (I think it counts Mestre as well) it's ~15% and that's the highest it found.
In bigger cities, it might be closer to 20-30% of their economy.
Take that away, and it would have a cascading effect through entire countries.
https://assets-global.website-files.com/6329bc97af73223b5759...
Unless you count the historical city center of Venice as a big city I doubt you'd get many big cities getting even close to those numbers
I can't easily/quickly find some numbers but if we want to accept, with a grain of salt, Gemini research on this even in Venice (I think it counts Mestre as well) it's ~15% and that's the highest it found.