You don't have to buy a new computer to get Wi-Fi 7 speeds. There are external Wi-Fi dongles, such as the Asus RT-BE58 Go or Acer Wave D7, that you can plug into an available USB port to get Wi-Fi 7 ...
You can do tons of stuff with a computer that most hardware NAT-routers cannot do, like having firewall software run on it, provide services (print (I know the SMC routers also have this), file, proxy ...