- Fast gaming computers that are only used to run benchmarks.

- Fancy photography gear that is only used to take pictures of resolution test charts and cats.

- Expensive guns that are never taken to the shooting range.

- High-end musical equipment that is only used for "noodling" (goofing off).

But modifying a 3D printer is cheap and fast (in labor time, printing stuff is slow, but it's not work), while parts for any other use tend to take much more time designing and applying. So that ratio is misleading.

I knew a guy like this. He also had 2-3 other bikes that he actually rode, but he spend a lot of time and effort (and money) building his Dream Bike. He was always waiting for some part to be shipped from some tiny manufacturer in Italy or Spain or Japan or Canada, and by the time it arrived he would have read about this other company that had an even smaller/thinner/lighter part, so he would order that as well and wait until he had both parts before meticulously compare them. And once he had managed to finally assemble a complete bike it wouldn't take many rides before either something broke or he decided something wasn't quite perfect so he would take the bike apart again and try to find an even more perfect part.

i built my own bike when i was young, but mainly because it was cheaper to get a quality bike that way and easier than saving up the money for a brand new bike. in the end riding is more interesting, so now that i can afford it, i just buy what i need.

You could have a goal which is to compete at the highest level that you can and push your abilities to see what you can accomplish, which you might enjoy doing. If you aim for this there's also plenty of scope for losing the deeper goal of just, having fun and enjoying your life.

In this respect I think the gaming and cycling examples can be qualitatively similar.