[Samsung Galaxy Z Fold 2 Questions & Answers] apprentice:
It's simply because the S20 series phones have the largest user base, so it makes sense to target them for the best possible and consistent bug reporting.

Samsung users don't really see the huge benefits of each iteration of Android, because generally new features have already appeared within OneUI. Seems Google take on cool Samsung features each year ;)

So I am much more interested in what OneUI 3.0 is going to bring to the table (following info is from September 2020, so more features and amendments are likely since this release):

One UI 3.0 based on Android 11 – Beta Changelog September 2020

Home screen

Touch and hold an app to add an associated widget

Turn the screen off by double-tapping on an empty are of the Home screen. You can turn this on in Settings > Advanced features > Motion and gestures.

Lock screen

Dynamic Lock screen now has more categories,, and you can select more than one.

Lock screen widgets are improved.

Quick panel

See your conversations and media more conveniently in their own sections when you swipe down from the top of the screen.

AOD

Always On Display widgets are improved.

Accessibility

Get quick access to the most important accessibility settings during device setup.

Get recommended accessibility features based on what you use.

Set the Accessibility shortcut more easily in settings.

Sound detectors now work with your SmartThings devices such as TVs and lights to give you more visible alerts when the doorbell rings or a baby is crying.

Samsung Keyboard

You can find the keyboard in settings more easily under General management in Settings, and the settings have been reorganized to put the most important ones first.

Samsung DeX

You can now connect to supported TVs wirelessly.

New touchpad multi-gestures let you change screen zoom and font size more easily.

Internet

Added ability to block websites from redirecting you when you tap the Back button.

Added warnings and blocking options for websites that shot too many pop-ups or notifications.

Rearranged menus to make things easier to find.

Added several new add-ons, including one that translates websites.

Added option hide the status bar for a more immersive browsing experience.

Increased maximum number of open tabs to 99.

Added ability to lock and reorder tabs.

Improved design for tab bar which is now supported on all devices.

Ended support for Samsung Internet edge panel.

Contacts & Phone

Added the ability to edit multiple linked contacts at one time.

Added an option to help you quickly delete duplicate contacts.

Enhanced the search experience.

Extended the storage period of the Trash bin from 15 to 30 days.

Phone/Call background

Added the ability to customize the call screen with your own pictures and videos.

Messages

Created a Trash bin to store recently deleted messages.

Call & Text on other devices

Added the ability to turn Call & text on other devices on or off with Bixby Routines.

Calendar

Events with the same start time are now shown together in month and agenda view.

Reorganized options for adding and editing events.

Improved layout for full screen alerts.

Reminder

Improved layout for full screen alerts

Digital wellbeing and Parental controls

Added trends to your weekly report. You can see how your usage has changed since the previous week and check your usage time for each feature.

Added phone usage time while driving to the weekly report.

Added a lock screen widget so you can check your screen time without unlocking your phone.

Added separate profiles for personal and work modes so you can track your screen time separately.

Camera

Improved auto-focus and auto exposure functionality and usability.

Improved stabilization when taking pictures of the moon at high zoom levels.

Photo editor

Added the ability to revert edited pictures back to their original versions.

Bixby Routine

Grouped preset routines help you get started quickly and learn how to build your own routines easily.

You can now see what actions are reversed when a routine ends.

New conditions have been added, such as a specific start time, the disconnection of a Bluetooth device or Wi-Fi network, a call from a specific number, and more.

New actions have been added, including talking to Bixby and accessibility actions.

You can add a customized icon for each routine and add routines to the Lock screen for quick access.

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