the Home Assistant under DietPi is a little limited and lacks the supervisor and plugins
But this is a limitation of HA due to it’s dependency and not of DietPi. Theoretically you could install Home Assistant Supervised on DietPi as well, but dependency are quite strickt and conflicting with some DietPi functions, like Network Manager. I did a test a year ago and it was working (somehow) Home Assistant Supervised on DietPi - #8 by Joulinar