I would argue that this hasn't been the case for at least the last 15-20 years it may have been true in the 1980s but any decent manufacturer will be using components that can easily withstand shutting down / startup thermodynamics.If you do that, the electronics will wear out due to constant temperature changes.
This is a devilish dilemma: yes for a smaller carbon footprint it seems ok to power off unused equipment, on the other hand power cycling and specially the startup of electronics adds a lot to aging of components. A shorter life time of the equipment that it often power cycled can be expected, which increases the carbon footprint because you have waste and need to buy new equipment.I've been powering off one of my router's each night for the last ... um decade or even more. The current model is an A86U. Powering it off works like a charm; haven't had any hardware issues. However, before powering off it is properly shut down ("halted") by a simple cron job because some services are running on it.
Why powering off? Simple: because it's only used for a few hours in the evenings. No need for it to be idle for 12 or more hours each day. And it's just one of the factors that contributes to a smaller energy foot print these days.
The second router will probably face the same fate.
But the question remains: does it have a lasting impact on the router's probability to die earlier
This specific router has a little bug in reference design application of MT3125 step-down converter. The more often you cycle the power, the more chances to end up with a dead router. I don't know if Asus fixed it with later AC86U models, but it's a common issue.
Welcome To SNBForums
SNBForums is a community for anyone who wants to learn about or discuss the latest in wireless routers, network storage and the ins and outs of building and maintaining a small network.
If you'd like to post a question, simply register and have at it!
While you're at it, please check out SmallNetBuilder for product reviews and our famous Router Charts, Ranker and plenty more!