Trackball vs a Regular Mouse- When and For Whom?

EIGIIS 2.4G Ergonomic Trackball Handheld Finger USB Mouse Wireless Optical Travel DPI Mice for PC Laptop Mac Left and Right Handed

Logitech ERGO M575 Wireless Trackball Mouse - Easy thumb control, precision and smooth tracking, ergonomic comfort design, for Windows, PC and Mac with Bluetooth and USB capabilities - Graphite

Kensington Expert Wireless Trackball Mouse (K72359WW) Black, 3.5" x 6.1" x 8"

What is a Computer Keyboard? - Parts, Layout & Functions

I'm irrationally excited for this trackball gaming mouse

ELECOM Relacon Handheld Trackball Pointer, Ergonomic Thumb Mouse for Right or Left Hand, Bluetooth, 10 Buttons for TV, Presentation, Game, PC & MAC