In my view, it depends if you want the end product or the experience of building your idea. If you're in it just for the experience, sure, go for it anyway. If

In my view, it depends if you want the end product or the experience of building your idea. If you're in it just for the experience, sure, go for it anyway. If you want the end product, ask yourself: does the existing solution fit exactly what you need, 100% perfect? Or are there things missing, or the smallest detail that bothers you for some reason? Most of the time it'll be the latter. In that case, build it. It may not make you rich or famous, but you'll have something that you love to use and you're proud of. That's enough for me, at least.