If Reduce Motion is on in System Settings → Accessibility, gliding is turned off automatically and the caret behaves like a standard one. The same switch stills every other animation in the app; the small delights page lists them.
Writing
The caret
An insertion point that glides between positions instead of jumping, and how to tune it.
The caret in Glassine is drawn by the app, not by the text system, so it can move the way a thing moves: when you press an arrow key, click somewhere, or type, it glides to the new position over about a quarter of a second, easing out, instead of vanishing from one place and appearing in another. It takes its colour from the theme — usually the accent — and its blink is a soft fade rather than an on-off flicker.
Everything about it is in Settings → Caret.

