I haven't left big tech, though I'm currently taking steps to switch careers into game dev, and will likely be looking for a smaller/indie team in that space. The way I see it is that it's not a "step down" if you end up happier. As long as you can afford to pay the bills and are happy, there's no such thing as a "step down" or "step up" -- those are just cultural judgments that don't matter.