Why is a skill different from a strength feat?
A deadlift is a strength feat. You load a bar and lift it. The movement pattern is simple. The demand is muscular force production. Train the muscles, train the pattern, add load, repeat. The progression is linear and the feedback is immediate: either the bar moves or it does not.
A handstand is a skill. You balance an inverted body on two hands over a shifting centre of gravity while managing proprioceptive feedback from your wrists, shoulders, hips, and ankles simultaneously. The movement pattern is extraordinarily complex. The demand is neuromuscular precision. Train the nervous system, refine the pattern, accumulate volume at the correct intensity, repeat. The progression is non-linear and the feedback is subtle: you held it for three seconds instead of two, but you cannot feel why.
This distinction determines everything about how you train these movements. Strength training improves with high intensity and adequate rest between sessions. Skill training improves with high frequency and low intensity per session. Trying to train a handstand the way you train a deadlift produces frustration, shoulder fatigue, and no discernible skill progress.
The nervous system learns skills through repetition of high-quality attempts. Each quality attempt adds a small increment of neural mapping to the motor program your brain is building for the movement. A poor-quality attempt, one where you are fighting exhaustion, is a low-quality signal that may partially undo previous mapping. This is why skill practice should always stop before fatigue sets in. You are not training the muscles to failure. You are training the brain to map a pattern.
Both the handstand and the planche have strength prerequisites that must be met before skill practice is productive. Below those prerequisites, you are trying to run a program on hardware that is not yet capable. Address the hardware first. Then install the skill.