Most of the time, yes. Almost all glass can be replaced and upgraded with newer multi-pane glass. You can also get “Low-E” (Low Emissivity) glass which blocks ultraviolet radiation. Those UV rays are what cause furniture and carpet to fade.
If the inside of a multi-pane window is foggy between the panes of glass, that is a sign that moisture is getting in and the seal has failed. This is another sign that the glass may need to be replaced.