The idea was that a Pi makes sense sometimes, and other times it doesn't. I know people using a Pi for one GPIO pin. This can be done just fine with an Arduino or an ESP8266.

I for one run a Pi with PiHole, Wireguard, Unifi controller, NVR, MQTT, etc. and a few more GPIO trinkets like Zwave. No ESP could practically handle all that, an x86 would be overkill in terms of size, noise, temperature, and power consumption.

On the other hand I use ESPs for things like "smartening up" my door intercom where even a Pi Zero would be overkill.