For many of us, it is NOT that simple. Most professional 3rd party media creation hardware and software has not yet been updated or certified for Tahoe. This is especially true of recording DAW software and plugins. Apple is notorious for making unexpected changes that impact such software as well as audio interface hardware drivers. Even the recent security-related app restrictions to a “sandbox” has broken fundamental and important features (an example is ARA, for those in the know).
While you can blame the 3rd party software companies for not updating their software for the new OS, it is also unreasonable to expect them to do so every year and every time Apple makes such changes on a whim. Even Apple’s own software has been impacted by such changes. The workaround for Logic Pro is to run it using Rosetta, which not only negatively impacts the efficiency of processing within the app, but is also a solution that will not be available in the next OS release. Apple already announced that Rosetta will be retired for OS27.
Professional audio and video software and hardware can be very expensive. Creators rely on it to earn their income. They can’t take the risk that upgrading to a new OS version will render their equipment non-functional. Even worse, it can prevent accessing previous projects that utilize plugins that are no longer compatible. This is seriously a valid case of “if it ain’t broke…”
If you use your computer for anything more than browsing the web and sending email, making the decision to upgrade your OS is not simple, and it is reasonable for Apple to allow us the choice to not upgrade without nagging us to death while we are trying to be productive.