Development time: the core editor took a few weeks of focused work, but I've been iterating on features for a couple of months now (slash commands, markdown mode, table editing, etc.).
Regarding Tiptap: it's a great project and I have a lot of respect for it. They're solving a different problem though. Tiptap is built on top of ProseMirror, which gives you a proper document model, collaborative editing, and a very composable extension architecture. If you're building something like Notion or a collaborative SaaS editor, that's absolutely the right choice.
The trade-off is complexity and size. Tiptap pulls in ProseMirror and its own packages, easily 200KB+ of dependencies before you even add extensions. You need a bundler, a build step, and you install features one by one as separate packages.
Zero WYSIWYG comes from the opposite direction. It's a single JS file and a single CSS file, about 120KB total, zero dependencies. You drop a `<script>` tag in your page, call `init()`, and you immediately get it working.
It's really aimed at a different use case: traditional server-rendered sites (PHP, Django, Rails...) where you just need a reliable textarea replacement in your admin panel without introducing a build pipeline or a framework dependency. That's the world I come from, and that's the itch it scratches.