Is slow internet speed a sign of a dying Apple TV 4K box?

SneakyPeeves wrote:

I haven’t. But we have had the same setup since we got it 5 years ago. Nothing new added. But worth a try. If that doesn’t fix it, any other thoughts? Thanks!

My initial thoughts are that hardware failures rarely affect network speeds. Mostly when hardware fails it is due to the power supply which is obvious by failure to turn on or random device shut downs from excessive heat.

If after switching units, the older Apple TV still shows slow network speeds I would first try to reset and update the device using these steps. This will wipe all info and reinstall the OS:

Reset or restore your Apple TV to its factory settings - Apple Support

Another thing to consider is if your Wifi network is using the 2.4Ghz band. I'm not sure the capabilities of your router, but if it is capable of both 2.4Ghz and 5Ghz networks, I would create a 5Ghz only network and try connecting to that. With some dual band routers they will automatically choose the frequency and some will default to 2.4Ghz if farther away from the router and by forcing it with a 5Ghz only band it will reduce interference. The 2.4Ghz band is notorious for inference when you get more than 3 or 4 devices. The channels that each device use to connect on the 2.4Ghz band will start to overlap and reduce performance. I have seen this happen on a single device without affecting the others for no apparent reason. More information on the difference in these bands is available here:

Optimize your Wi-Fi networks for Apple devices - Apple Support

It is unclear from your post if you have tried switching the Apple TV boxes to determine if it could be network related or maybe interference from nearby devices.