Yeah I actually help out a friend's family business a lot and we recently had to fix the program for something. It's a foxpro application rewritten in '89 from an original dBase port from earlier in the 80s. I legit had to bust out radare2 and hexdump(analysis)/hex fiend(editing) in order to get the changes done because the original programmer passed away (RIP). Was quite the learning experience but I'm glad that things were simple enough back then to make it something like an easy introduction into the world of reverse engineering for money.
I've seen even older in use. There's an auto parts store in the capital city of Costa Rica which was still running dBase III for its inventory system on a green phosphor screen IBM PC. Not sure if that store is around post-pandemic but it certainly was running around 4 or 5 years ago. Wish I got a video but it's in a particularly sketchy area that I don't really have any reason to return to.
Also, if anyone else ever has to dump an old database to CSV or whatever, I found perl to be the best tool for the job as it handles old encodings just fine. You can go from ancient database to spreadsheet really easy this way. Here's the ticket: