So, how long should these routers last before starting to "flake out" & need replacing?
On the internet since 1995, I never had a router fail on me. If and when I do replace one I do it "just because" I feel like updating something. When I do upgrade I tend to upgrade not to the most current wifi AX but to the past "current" Wifi AC
Example - I have been on WiFi AC for the longest time now. I choose routers not on brand name but on range. Routers with clean noise free transmitters and receivers are more important as in my case of having 300 Mbps service.
Ive always successfully used a single center of the house placed router in our past 3000 sq ft home as I do now in our smaller home, never an issue as close to full service speed throughout the house. Any given time up to 25 devices connected, granted all do not run at the same time but a significant amount do.
After a few years of flawless service from our TP Link AC router, (which still works, I still have stored) for fun I switched into a Motorola MR2600 AC router years back, still works flawlessly as well. Both these routers cost pennies compared to some. Around $100.
I cant count maybe on one hand the number of times I had to re-set a router in the last 5 years and if I did it was because a device wasnt working properly, not the router.
As someone pointed out one time it is true if the router isnt supported any longer you may not get security updates ... I dont worry about that even though my current router is still sold and some of the biggest name brands and expensive ones have had issues.
It's true that I seek value in things, but this doesnt mean I discredit those who wish to spend hundreds more. We all do what we do for a reason and satisfaction. Example if you like to play around and get in deeply with settings in the router a basic unit will not let you do as much.