I'm not stopping you from creating Void if that's what you want. Perhaps it would be a fantastic desktop (and mobile) environment that works for everybody, and I would certainly be willing to give it a try (just as I have tried most of the existing Linux desktop environments). Perhaps it would become really popular, and displace all of the existing desktops due to its self-evident superiority.
But sadly, you're not going to find this out until after you've spend thousands of man-hours building it, debugging it, testing it, documenting it, persuading Linux distributions to include it and persuading end users to try it. And even if it does become more popular than GNOME or KDE, you're still going to have an uphill struggle to convince the millions of Windows and Mac users to switch to it, given the issues with familiarity and program compatibility that chakkman and others have pointed out.
Much as we might wish it to be different, people don't always use a tool just because it's the best. They use what they are comfortable and familiar with.