That'd get you the chip which you'd have to solder to a board. Possible and feasible but not as easy as plugging in an ESP8266.

You would not only have to solder it to a board, you would also have to provide a radio peripheral. At which point you're pretty much looking at a pico W, which just isn't as cheap or small as a D1 Mini (or similar).

Wasn't there previously some problem with using Pico boards and you had to use a fork because PlatformIO were trying to get vendors to pay (for something they never asked for), and then kicking up a big fuss when they didn't pay up. I say vendorS because they are now trying it on with Espressif also. It seems like a very strange funding model. Did that get fixed? It was a depressing state of affairs when I last looked.

You can get a three pack of esp32 dev boards (with headers) for $6 from Aliexpress. For that you get:

1) Wifi.

2) Much more robust ecosystem, including esphome (the subject of this post).

Plus the 99 cents for flash chip.

Plus the 99 cents for the PCB.

Plus the 99 cents for misc parts like regulator and caps.

Plus the $4 for the wifi module.