I have a Dell Laptop that has lasted so far 10 years even though it's getting outdated. And dell desktop I've had for 15 years that still is working fine.
The 15 year old Dell Desktop is working fine and I've updated the operating system.
I expect it will still be working another 15 years but I'll likely be buying a new desktop computer before then since I'm unable to update the operating system anymore.
Most computers will be outdated before they actually stop operating.
In my opinion Dell Computers are good computers and most office environments use Dell Computer systems.