Again, you tend to overlook things that are already on the market, like https://www.raspberrypi.com/products/raspberry-pi-400/

or the myriad of SBC-based computers like this. The only thing you should do is to install an OS, which is something everybody tends to do and succeed nowadays.

I've bought into marketing, and bought myself a Pi 400. It's abysmally slow for everything.

It feels like eeePCs of yesteryear. Underpowered and slow

I fully agree with you, but it's still a PC, although not envisioned for the power users, but for the people who just need to do the most basic of stuff (e-mails, maybe a few documents, etc.), that's what a ~6W CPU can deliver.