You can't rewrite something complex. If you try to rewrite it you'll not achieve feature parity so it will be something different at least when you're building

You can't rewrite something complex. If you try to rewrite it you'll not achieve feature parity so it will be something different at least when you're building it. And you will perpetually chase your target. You MAY try to build something somewhat compatible starting small (not a replacement) or you can fork and gradually diverge