Not a lot. However, there are businesses that only take cash, so I have a little on hand for that. I don't expect the downfall of civilization, and frankly, if that did happen, some paper rectangles and pressed metal discs wouldn't be of much use.
But mostly I pay for everything in other ways. Seems safer, contamination-wise, these days, though "safer" is of course a relative term.
And yeah, any cash I have tends to sit around for years. I don't use it often.