I had some micropython boards using mqtt to talk to HA, great for sensors, but have switched most to Esphome, it integrates easier into HA.

I've got a wall switch on the coffee grinder that switches off after a min, because otherwise it's power supply humms.

I've got a epaper display on the fridge, battery powered that tells me what type of recycling goes out this week (uses deep sleep mode on esp to wake up every 18hrs, pull info from HA calendar to display, report it's battery state, so we can get a mobile alert to charge it every couple of months)

A esp8266 board that's got 6 relays, hooked up to dampers on the central air conditioning, turns on or off airflow to different rooms.

Power monitoring for the washing machine to send a voice message when the washing machine is done, using Athom Tech plugs that come with Esphome pre installed

Another athom tech plug on our electric blankets, nothing like having them automatically come on and never having to worry about leaving them on (will turn off after 3hrs after they automatically or are manually turned on)

Several accent lights using Esphome powered rgb light strips, could also use wled, but Esphome is good for this too

Esphome is amazing with home assistant!. Build a climate control with it for my server room for example. Pure esphome sensors and relays on a single board.