If you watch the ads on TV, you'll know that dozens of new products are launched every month. New foods, new beauty products, and so on. Just when you think you've found the perfect shampoo for you, the company brings out an ever better version. Or at least they claim that it's better.
It's the same with software. In the beginning, for example, there was Visicalc and Lotus 1-2-3. Nowadays it's all Excel or Libre Office Calc, for anyone who needs spreadsheets. The old products were discontinued by the vendor, or the vendor went bust.
Back in the 1980s and 1990s there were thousands of computer games which were great fun to play but which were subsequently abandoned by their maker. The computer industry refers to such programs as "abandonware". And if you know where to look, you can find retro gaming web sites from where you can download lots of abandonware games to play on your PC.
One of my favourite sources of abandonware is https://www.myabandonware.com/, where you'll find upwards of 13,000 games including some big-name ones. Not all of them will run on modern hardware or under Windows 10, so you may also need to download an emulator or create a virtual machine using a product such as VirtualBox or VMware Player.
But if you want to re-live the good old days of computing, try https://www.myabandonware.com/ and see what you can find. But remember that these programs were not built for today's PCs or operating systems, so it's safer not to try them on your best computer except within a virtual or sandboxed environment.