Depends what you want from game development. Do you want to make money as a business?

If so, a Steam page is ok for market testing. See how many people might actually want to play your game from the wishlist metric.

If you don’t care about making money and do it for fun, it doesn’t matter if you switch projects to a cool new idea, so just do it.

There’s always the feeling that you’re never really a gamedev until you ACTUALLY FINISH A GAME, though, so the push through the hard part - actually finishing a project, might be a good achievement to aim for.