Did you know that videos from the 70's, 80's, 90's and 2000's are analog media? Analog formats such as old VHS tapes, MiniDV tapes, 8mm and hi-8 tapes, will naturally age and degrade because not only is the medium—the video  tape—slowly degrading, but each time you play the video the magnetization of the medium itself degrades as you play it thanks to the flimsiness of the media. But because it is analog, the image just seems to be faded or sputters.
Digital video—on the other hand—is strict on or off; data bits are  ultimately 1’s or 0’s and nothing else. So assuming the files are in  perfect condition in years, decades from now, the video will look  the same as its converted.
Time, heat and moisture directly impact the degradation of videos/films/slides/photos.  Don't wait for your videos to be ruined, have us convert them to digital format to be preserved forever!