> food are free market because they are easy to get substitutes for in most of the western world (move to a different neighborhood, buy different food)

In the US, a very small number of corporations own nearly all the supermarkets.

You can move all you want, it is the same stores (possibly under different brand name, but same ownership).

Don’t go to a supermarket then? Use farmers markets, local butchers, and local coops if you don’t like supermarkets.

Grocery stores have thin margins because they have competition or threat of it.

Housing in Ireland isn't a free market. We have had a chronic shortage of housing for decades, but the influx of asylum seekers has put more pressure on it. Renters stand in lines half a mile long to view a grotty shoe-box that costs more than a mortgage. But yeah, maybe in other places it's different.

Yes, food is a free market right now, and in addition, it's subsidised (well, production is). Wait 20 years though, if climate change driven storms and floods destroy whole crops, that could change things dramatically.

You might be surprised how hard “move to another neighborhood” can be for some.