I disagree with your assertion that the safer bets are less satisfying. If my users like and use my app over our competitors', that's more satisfying to me than

I disagree with your assertion that the safer bets are less satisfying. If my users like and use my app over our competitors', that's more satisfying to me than building something challenging that no one uses or likes. If you're working on something in a crowded market, designing your product to stand out/work better than the rest can be just as challenging (and satisfying) as writing something technologically complicated.