Though many of the alternatives have rather poor software and support, and as you can't just load an iso meant for a raspi you have to do most stuff by yourself from scratch.
As an example, I have home assistant running on both a Raspi and an Orange Pi board. One of them was a simple iso flash and is still supported and updated, the other took few days of tinkering to sort out and the newest Debian iso for it was uploaded in 2020.
But if you know what you are doing, you can get great hardware for really cheap.