Very funny, I stille have an old TPlink running now for 6 or 7 years, my parents had an old linksys that only did 2.4GHz running for 13 years or something. Before i replaced it for them.

I honestly don't know how a router breaks. It can become outdated or obsolete such that it can't interface correctly anymore or it can have a hardware failure that kills it by surges or physical damage, or it can be completely unsecure because it hasn't been updated in a decade but routing is "fairly simple" and just getting data throughput isn't rocket science software-wise.