There are an array of macOS Mojave desktop and finder upgrades that could be what pushes you over the edge to try the beta.
One of the biggest upgrades is the new Stacks feature on your desktop. This keeps all of your desktop documents organized better. This is an even bigger deal if you use iCloud to sync your desktop between devices.
When enabled, Stacks keep your documents grouped by type, dates or tags so that your desktop is cleaner and you can easily find the documents you are looking for.
Another cool feature is the dynamic desktop that changes over time, showing the sun or moon crossing over the Mojave dunes while you use your Mac.
Finder now includes a new Gallery View so you can sort through photos faster. Quick Actions lets you password protect PDFs or run Automator Actions. Quick Look shows you a full size preview of a file and lets you edit images and pdfs as well as trim audio and video files.