I got my Pi4 to be a media player - LibreElec or Kodi - for my old, not-smart TV. It plays my library of CDs&DVDs, frontend for OTA TV, and a variety of streaming services. Fanless, so it doesn’t distract from audio, low power, so I don’t mind leaving it on 24/7. You can configure it to listen to a USB IR receiver, but I control mine from phone via web. The actual media library/NAS and tvheaded run on an old desktop in another room.
My favorite thing is all the sensors you can hook up. Adafruit & Sparkfun have a wide array of sensors with breakout boards for simplicity and well documented python libraries. I started just logging temperature, humidity, then air quality, CO2 to my own database and web page, but eventually expanded to full HomeAssisstant system.
Pihole.
Georgia still has among the lowest per-kWh tariffs in the country, at $0.086/kWh (0.0806 in winter). Plus $14/month service charge and 20% taxes & fees. Compare California at $0.40/kWh.