The correlation being that older cameras that are still working and performing well, may indicate they were built of a high quality. The OP asked about older cameras still being used regularly, not just old cameras.
All of my film cameras are long gone, but I still have my first good digital camera, a Sony Mavica MVC-FD98 a 2.1 Megapixel camera and I do still use it, but only a few times a year. I had to buy a USB external 3 1/2" floppy disk reader in order to keep using it, to continue to download my photos, but this was my first good digital camera, bought about this time of year back in 2000. The quality has always been quite good.The attached photo was taken in 2000 and is straight from the camera with no editing at all.
