Both look like stillness from the outside. Only one of them returns you to yourself.
Rest restores your capacity to show up. Avoidance quietly shrinks it. The test I use now is simple: after this, do I feel more able to face the thing, or less? A nap that sends me back to the desk clearer is rest. A fourth hour of scrolling that makes the same task heavier is avoidance wearing rest as a costume.
Name it honestly and you get to choose again. That is the whole point.
