>It's much more difficult to buy the ESP32 as an MCU than it is to buy it as a SBC, with ports for power and I/O already on a PCB (often with through pins, to land on another PCB, like the arduino hats). And I don't mean "it's difficult because you have to solder" - I mean "it's difficult to find many places that sell it".

1. Go to mouser.com

2. Type ESP32 into the search bar

3. There's your part.

Its difficult to buy a very specific nut or bolt from Amazon (their nut/bolt search interface doing precisely nothing it appears to be intended to do). That doesn't mean McMaster-Carr doesn't exist. You're just going to the wrong store.

If you're in particular referring to how hard it is to find a PDIP package (that is, a through-hole package) for an ATMEGA MCU, that's because they don't make them anymore. Insofar as I'm aware, Espressif has never made a through-hole ESP32 module, but maybe they made one with castellated edges?

But an ESP32 module is as easy to come by as a surface-mount ATMEGA328P. Which is to say, very easy.