What does 'lifetime' mean? Mine are nearly all original.
Modern windows don't last very long, because the seals leak, and the argon gas or whatever leaks out. The glass is still good, but the insulative quality is gone.
The parent poster didn't realize that if you don't have double pane windows, you have single pane windows, which have no gas to leak.
But my point was that windows, the glass part, lasts centuries, if not longer. Not the mere decades cited upstream.