Stock-up while you can, I see TDK Europe recently killed-off the only tape they still made, the legendary TDK-D, meaning that as far as I can tell they no longer make cassettes of any description. My favourite chrome tape (TDK SA) was killed-off a couple of years ago and now NOS blanks are starting to ramp-up in price on eBay, particularly C90s. Metals have been unavailable for years and some of the prices they fetch are eye-watering.
Technolgy marches on and it doesn’t care who or what it kills, unfortunately. When I was a teen/young man in the 80s and 90s, cassettes were so ubiquitous that I honestly didn’t think I’d ever see the day when blanks were discontinued, just like 35mm film.