It's not that simple. Each platform has different formats and limits. For example, webtoon has width limits and won't do PNG (the default I save my comic in). So they require special formatting every time. Then some require thumbnails, each with different limits, and you can't just add your comic page in. Each platform has a different method of posting. And if you queue up batches instead of doing 1-by-1, you need to track which one goes where. Some have different tagging systems, too.
It's time consuming to make it all decent in the end.
Then there's the question of how are you promoting each platform? Are you cross-linking everything so people can read on their preferred site? Are you participating in the communities to build your visibility? And if you're not promoting it for that platform.....why post there? You'll be drowned out by everyone else's content and it won't be worth the effort to keep posting there.
