We all tend to overthink as creatives.
Is the work good enough, what can I do better, what do other people think, what is my style...
Theses questions, and the kinds of thinking they unconsciously engender are toxic to creativity.
Instead of performing the act of creation, you procrastinate and worry.
And when you do act, you're subconsciously forcing a certain outcome - blinding you view on what you have actually made, closing that door and burning that potential goldmine.
Doing dailies, writing a blog post, making a painting every day rids you of this burden.
The time limit is beneficial for 2 great reasons
Over time it builds huge volume, volume that you can look back on and grow from, that will spark more ideas and tell you more about your creative self.
It forces you to live purely in the act of creating - since you HAVE to produce something, you won't treat it as preciously, you're more willing to experiment. It stops you from overthinking and unburdens your creativity of the responsibilities and prerequisites you normally impose on it.
Discipline yourself to carry out something creative, that's relative to your level, every day and you will reap the rewards for years to come.
It is that simple.