Now that I'm writing this, I suppose one useful concept is that of constraints promoting creativity by forcing you to come at the blank canvas from a different mindset than you're used to.
I suppose there are some times to struggle and grow but other times, like a competitive swimmer shedding his 'drags', to engage our full unhindered capacity free of such artificial handicaps.
Another musical example for me is the band Amaranthe. They usually make extensive use of modern production techniques but their talent is also very evident when they're unplugged:
https://www.youtube.com/embed/J4Jhpx2Qmz4?start=61&end=290
Music video for the same song: https://youtu.be/D8lV1To-_fU
And even if the "restricted tools" do make a difference we are splitting hairs here, because we can create a similar equivalence, e.g. a c++ program with artificial restrictions: A program where you can't use your own classes or structs, or a program that can't be bigger than 1KB, and so on.
It was difficult, but we really learned a lot.
The old lady's choice may have made perfect sense from her point of view.