Food has pretty much the most inelastic demand curve imaginable. There's no way that agriculture will disappear without subsidies. Prices might increase, sure. But anyone who has any money will pay whatever prices are necessary when the alternative is literally starving to death.

If you're referring to agriculture disappearing from the US, that definitely wouldn't happen either. Some of it might, but not the majority. Most countries don't heavily subsidize farming to the extent that we do, and transportation costs are non-trivial, especially for fresh produce or anything that needs freezing.

Not always true. In New Zealand we had subsidies for farmers (about 40%) and then they were taken away. The removal forced the farmers to innovate and now we have very efficient farming methods that have far less environmental impact. 2/3 of NZ's exports are agricultural.

https://en.wikipedia.org/wiki/Agriculture_in_New_Zealand

Edit: The thing I found most interesting about this is agriculture was deregulated by the left wing government in what is a very socialist leaning country. Kiwi's are very pragmatic.

The EU has successfully tested this and removed any subsidies to the sugar agricultural sector. The sugar industry in Europe has not imploded. In fact, it’s just adjusted to the new reality of not being subsidised. Other than that, it’s pretty much business as usual.

We had agriculture before the subsidies.

Agriculture, at least in the US, has always been subsidized. As a country we used slave labor (free labor) to subsidize agriculture, and then over time we gave away an epic amount of land to white farmers (via the Land Act of 1820, the Homestead Act, and the Morrill Act of 1862).

We also had lots of starvation before subsidies too.