Imagine you're pushing a collection of rocks up a hill.

The hill is getting steeper as you go, it's getting hard to keep the collection together and get it further up the hill.

If you crest the hill and hit viability, it will transition to downhill; orders of magnitude easier.

But how do you know if you should power through to the top of the hill that others can't see yet, or if you're investing increasingly desperate effort in a dead end?

An important skill: to learn when to pull up out of a rabbit hole when you're hitting diminishing returns.

It's easier for someone watching you to identify it than for you to self-identify.