Nearby Venice there's so much interesting stuff and small cities, a bit further are big cities. None of them really struggles with tourists as much as Venice. Maybe you'll see a huge line for Firenze Duomo but that's it, streets and other sights are practically lineless.
Why Florence struggles with Duomo and Venice struggles in general? Because they're famous all over the world for things they're struggle with. Everyone know about floating city of Venice, and Florence's Cathedral. Those things are being romanticised for centuries.
All Italy has to do is start load balancing tourists. Advertise other sights in the area, build easier public commute to other stuff. They have means to do so, they have tourism ad budget, they have 'city_name' cards which grant discounts to different sights.
I've been to Croatia this summer, they are struggling with Dubrovnik too. But most beautiful things are not there. Plitvice is like heaven and past 2pm I was walking there practically alone, Split's old city is as beautiful as Dubronik's and except 12-2pm is not crowded, beaches in Makarska and on Hvar are way more scenic and comfortable than Italy's and there's no crowds.
Go other places or rot in queues of over advertised sights.