> Who cares how/why they're there

The people who face them. The constraints are making the goal harder to reach. The goal is on the other side of the constraints and it takes power of will to refuse to remove them and keep pushing. This forces a different, slower, more difficult to reach solution.

> when stuck creatively in music production

So you're not introducing constraints, you're creatively trying out things to fix your problem. They're not a wall preventing you from reaching your goal, they're the bridge. Your constraint is the temporary lack of creativity, and what you introduce is the means to reach the solution faster.

> Really easy for me to skip these artificial constraints at any time, they still help a lot.

When you remove these you're stuck in a creativity block and failed to achieve your goal. When you remove actual constraints you make the goal easier to reach. It's a matter of perspective and what you want to achieve. You wouldn't want a long road through the mountains as your daily commute but it's probably lovely as a hike.

The only way to make the problems comparable is to set a programming goal of "write the most efficient code to do X" but for real work the goal is almost always "do X".