Extend selection is via the same select mode that vim already has, so that's 1 extra key prefix, and move selection is enabled by default, so regular move commands pre-select what they move over, so in some cases that's even saving you a keypress :)

Though it's not that it should be the only way to go (plenty of vim pros have adjusted), it's just visual feedback is very powerful, and lack thereof is a legitimate big challenge you shouldn't ignore in the "greatest" answer