It's genuinely hard to make a good design for something, but if you put the time and effort required, that's the difference between Atom and VS Code.
The only way I know how to make a good design, is to have a good Product Owner. Prototyping helps a little bit, User testing absolutely not. You can have five different PO working on the same epic and still get a bad design, but it only takes one to find the perfect solution.
That input box story is not different. They could have made the WYSIWYG feature compatible with the "old" input method by changing the visual without altering the character flow (eg: The <star>brown<star> fox). Apparently, no one thought of that...
If I'm imagining it correctly, it should work like this:
writing `help` will render it inline. A rendered `help`^H becomes an un-rendered `help
The rendering doesn't need to show the backticks, but it seems to me that it's perfectly reasonable to have it exist from the text-editing perspective.
The real problem might be that hitting <star><star>help<star><star><LEFT_KEY> can either move invisibly between one of the two stars (technically correct), or jump a star to place the cursor just after p (visually correct).
I would think the best solution is to have all editing keys (eg backspace, delete, insert-then-type) be technically correct, and all movement keys (eg arrow keys) be visually correct.
I think this is also how Typora does its markdown rendering, which was functionally intuitive in my experience (I stopped using it because it slowed down severely with any file larger than like 300 characters, so a worthless text editor, but UI-wise it worked well)
The only way I know how to make a good design, is to have a good Product Owner. Prototyping helps a little bit, User testing absolutely not. You can have five different PO working on the same epic and still get a bad design, but it only takes one to find the perfect solution.
That input box story is not different. They could have made the WYSIWYG feature compatible with the "old" input method by changing the visual without altering the character flow (eg: The <star>brown<star> fox). Apparently, no one thought of that...