GIGABYTE Model GC-WB867D-I (ver. 2) Bluetooth 4.0/WiFi Expansion Card
Let’s skip the “Why are you using this or Why are you even asking” so we don’t get off topic!!!
This is what I’ve been using for the past year. It’s a year old. How many years does this part usually last for?
Until it stops working or the standard is too slow for your use (more likely).
I’ve only had laptop wifi adapters fail, but that is probably physical damage.
I’ve been using pcie wifi cards for years without problems.
I wouldn’t consider this type of component a high risk failure part, such as a hard drive or PSU.
No moving parts and low power, yea, it’s not going to break any time soon.
A device like that will probably outlast your intentions on keeping it. The most likely points of failure are the two electrolytic capacitors, and they could last 20 years or more.