It really is! I built a system to monitor/control my wood stove with a pi. The GPIO pins made it easy-ish to hook up an infrared temp sensor over i2c. I found a relay hat that allowed me to switch 120 VAC to control the stove's fan. My pi 4B had plenty of power to run a Ruby on Rails server to build little charts/graphs, a config UI, and some cron jobs. Lots of very powerful Lego blocks, basically.
https://github.com/locofocos/wood-stove-rails