The new macOS Catalina update is underwhelming. It’s probably due to Apples new auditing process for better quality software releases. The most groundbreaking addition to macOS is sidecar - which let’s you use your iPad as an extra screen. Other than that they’re getting macOS and iOS to play nicer together and there’s some security updates.
From Apples website
Use your iPad as a second display for additional screen space. Refer to one app while you work in another, or see how a presentation looks in presentation mode on your iPad while editing it on your Mac.
They added new native app to macOS: podcasts, and they updated old ones like iTunes (now called music) and added a TV app. There are also updates to old stuff like notes, safari and photos. Syncing is cool:
All three services — Apple TV, Apple Music, and Apple Podcasts — sync your content through the cloud across your devices. Or sync it from each of the apps if you prefer using a cable.
Your macOS drive is now on it’s own volume, which means no apps or anything can mess with your macOS software. This also means a lot of apps that use kexts and other means of adding features will have to be remade for Catalina. This means a lot of unsupported software when upgrading.
Overall it’s pretty underwhelming and I won’t be upgrading to Catalina anytime soon.