Universal Control is definitely one of the most anticipated features of macOS Monterey, which was announced in June at WWDC 2021. However, this feature was never included in macOS 12 and iPadOS 15 betas, which led us to believe that Apple could delay it to a future release.
Now with macOS Monterey beta 10, Apple has labeled Universal Control as a “beta” feature, although it is still unavailable to users.
As demonstrated by Apple earlier this year, Universal Control lets users wirelessly control an iPad or even another Mac using the keyboard and mouse of their main computer. Unfortunately, Apple never made Universal Control available in macOS and iOS betas, and pretty much all references to this feature were hidden.