This kind of tech stuff isn’t really BIFL. However, you can extend the life of it by separating the components. So an OPNsense box for the firewall/gateway (this can last many years with very little maintenance), a separate WiFi access point (AP), and a switch.

Many consumer-grade Wi-Fi routers are all three of these components combined into one (usually) low-quality package. When one part of it dies or becomes obsolete, the whole unit would need to be replaced.

By separating the components, you can get better quality hardware (even if consumer-grade), and replace/upgrade them independently when needed.