It does, because everyone and their dog started releasing software that only runs on the latest version of macos. So if you are not running the latest macos, you can't use the latest software version.

For example, I used Sketch on my ond mac once and was quite happy, but then they dropped support for the OS version that mac was stuck upon. And since newer libraries resources etc all target latest version of Sketch, the version of Sketch I could run quickly became useless.

The worst is when an application updates itself just so it can stop running and tell you to upgrade to the latest OS version.