First you validate your idea by seeing if there is a potential market for it. Talk to people. See if someone is excited about it. Show them your work in progress.

See if there is already a company in that space and find a differentiator.

I’ve noticed the same thing: if the shape of the problem is still interesting after the novelty wears off and progress stalls, that’s usually the real signal. The visible demo work is easy; the hard part is exactly what you said—defining “done,” handling edge cases, and making systems behave consistently under stress. If those invisible constraints keep pulling you back, it’s usually because there’s something fundamentally worth building there.

You can tell because the product answers OP's question.

I’m not in the industry or part of a company yet—I’m still on the younger side.

I’ve had many ideas and I work on them, but nothing really takes off. I keep coming back to the same question: is this worth it? Especially because every idea I have, I run it by my friends—they love it, I build it, they don’t use it, and I’m left with a dead project, a half-empty wallet, and goals I could have pushed further with if I hadn't taken up the project.

Bit of an ad because I am trying my best to get my product out there everywhere.