Cannot do that if it acts as the always-on router…

Companies have regularly scheduled (weekly in some cases I know) maintenance windows affecting thousands of people. A home environment with an "always-on" router can surely find a 10 min window (say, 3 AM on a Sunday morning) where nobody cares.

Funny enough, instead of doing that every year, my policy has been "replace the machine if it breaks" and in general, I've gotten a good five-year cycle out of all my PCs without having to do disassemble-maintenance with an air can and a static strip. This has been good enough because I do enough high-graphics-demand gaming that five years is about the cycle on which some new-shiny has come out that renders my machine too old to play modern games.

Maybe I'm just lucky.