You don't need a Samsung account at all to use any of the addition features.
Some of the useful features off the top of my head:
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Long-press power button for torch (customisable)
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Edge panel, which allows quick launching of apps and shortcuts
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Ability to directly record the screen, or a portion of a screen, as a GIF
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Video out over USB-C, and DeX mode which provides a desktop-like experience (although I believe Google will be finally introducing video out with Pixel 8)
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Various multitasking enhancements such as: open any app in a popup window, change its transparency levels, enable no-pause multitasking so your split-window/popup apps continue running even if they're not in focus.