When you upgrade your desktop PC, plan for it to be the home server after that.
I got a rackmount case to transplant my old desktop montherboard into every 5 years. I also got a 4-port NIC so it can also be a router. My server is a 4th gen Core i5 and it's still plenty of power for a home server.
If you're a laptop guy, I'm not sure what you'd do. Maybe ask friends for their old desktops. The Win10 discontinuation next month would be a great opportunity to snap up some business PCs destined for landfill.
For Home Assistant, I think you either need Docker or a dedicated box. I kinda hate how there isn't a .deb package for it like literally every other service on my server.