For a weightlifting competition, those constraints are things like "don't use steroids" and "don't use an invisible string to assist you in lifting the weights".
For an art competition, the constraints might be things like "don't use AI to generate the image" or "don't hire another artist to do the work for you".
In all of these cases, breaking the constraints is still work. Using steroids is dangerous and may be illegal. Hiring another artist is time consuming and expensive. Getting good results from an AI model takes many iterations and a lot of tweaking.
If you just care about the result then it doesn't matter how the heavy lumps of metal were lifted, or who created the aesthetically pleasing artwork. But if you care about the competition, then these constraints are important.