I think some other terms cover this:

ambitions, drafts, mistakes.

Not a negative connotation with "mistake" either. If I had an idea and spent money on a domain name, but never take that idea to launch, it was a mistake to spend the money. But it was also a tiny bet, a necessary step in the direction of a launch. And I probably learned something along the way, which is the great value in mistakes.

The cost of undoing mistakes varies greatly. While I can sell a book I paid $20 for, and get a few dollars back, if I ever decide I want that book again, maybe I can go to the library, or maybe I can pay $20 again. If I give up a $10/year domain name, the odds are if I ever want it again, the cost will be much, much higher. Unused sketches and designs? Those are simply drafts, and drafts can be archived or discarded. The cost of storage is often inconsequential.

I think there's potential value in reflecting on unfulfilled ambitions, and maybe learning which of those past decisions weren't worth making. I'd say I don't think this article necessary puts forth a judgement of whether you should or should not have made those mistakes, or if you should make a change going forward, but merely puts it "out there" to reflect on.

Or just... thoughts, ideas and proofs-of-concepts...