A bicycle stays up by continuously failing to fall

A bicycle in motion is not balanced in the way a table is balanced. It is falling, being corrected, and falling again, fast enough that the correction reads as stillness.

Plenty of systems are stable in that second sense. The steadiness is not the absence of a force; it is the presence of a correction operating faster than the disturbance. Remove the correction and the apparent stability does not degrade slowly — it ends.

Worth remembering when something looks like it is holding itself up on its own.