If every action becomes predicated on waiting for the right mood to strike, you’ll find yourself falling into a negative feedback loop.
The second problem with motivation is that it will always need refreshing. Very often, without the additional fear of looming deadlines, motivation alone is rarely sufficient to compel us to action. You can think of any number of times you’ve told yourself you’ll go to the gym, or read that book, tidy your room, or start that diet. And even when you do it once, how often does consistency flow from that initial burst of motivation?
Motivation is great for storing and converting mental energy for a particular purpose - one burst at a time. It’s like a machine wound by a crank or lever.
However, it quickly becomes a short-term crutch. “It’s too early, my brain is still a mess”. “I haven’t eaten so my performance will be subpar”. “I have eaten too much and now I can’t concentrate”. “It’s late, so I won’t do it effectively”. All of these say “better to do it later, when I have sufficient motivation”. You’re making a prediction that a future version of yourself will once again find that perfect hormonal cocktail for one more burst of energy.