So let's say you want to keep supporting some EOL'd OS. Here's what happens in your development organization, sooner or later.
When an OS is still in some variant of maintenance support, and you have a bug that is caused by the OS itself, it can be fixed by reporting it to the vendor. Once you are past EOL, if you call and say, "Hey, we've got a crash, and we traced it back to a bug in libNSASpyReports.so," the response will be, "Yes, that bug is fixed in in version 4.3 of that lib, which is distributed in the supported version of our OS. The version of Glownig Linux you have is now past EOL, and the fix is to upgrade to a supported version"
For commercial operating systems, being past EOL means that you can no longer build new test machines. Eventually, your dev tools won't even run on the old platform. Visual Studio 2022 isn't supported on Win 7. Supporting an OS in the grown up world of commercial software land means you ran your regression tests on it. It means if customers report bugs on the platform, you fix them, or pass them along to the vendor. Test machine fails? It's gone. Can't upgrade the boxes, either. That's aside from the issue that any bug that isn't your fault simply can't be fixed now.
Last, but not least, at some point, the software you depend on to develop and deploy code eventually stops supporting the old OS, and you can no longer upgrade either. Want to upgrade FlexEra to 2022 R2? Your customers can't run their licenses servers on Windows Server 2008 any more. Want to upgrade to QT 6? Win 7 & 8 support is gone. New software almost never supports old platforms. Want to start using Intel's oneAPI multiplatform development tools? There's no Win 7 version, never will be.
Yeah, there will always be a handful of users (not just gamers, trust me, it's every industry) insisting that you should keep supporting ancient, unsupported platforms and formats, but eventually, their demands stop you from advancing your technology, and you have to pull the plug.