When you have a lot of resources, it can blind you to solutions. You face a struggle, and you assess your myriad options. They all have big drawbacks and high resource consumption, so you’re stuck with no solution or one that might cost more than it’s worth.
Then you take away all those resources and make the problem a must-solve. Somehow, you find one. And it’s pretty efficient.
I don’t know why, but it’s just too much to ask of the human brain to find these solutions when we don’t really have to. Resource constraints force exploration of corners of the brain otherwise missed.