Well, is says that the website itself was build by the tool. Non-semantic tags, divs instead of links, buttons instead of links, a lot of inline styles (which is a bad practice), deep nesting. So inline styles will make caching css impossible, so high load times, not good for performance. Deep nesting makes the problem even worse. So the result is a slow bloated inaccessible code, but the result may look ok. If all you want is a pretty picture - than yeah, it is a great tool.

I prefer this approach - https://github.com/seek-oss/playroom Just create your components and add them to the sandbox and allow your designers to play with them.

Think he's point was that GUI products in this space is extremely difficult to get it right due to the explosion of edge cases and general complexity.

There have been other React IDEs in the past, and they've faded off into obscurity because of factors I am not familiar with but one in which parent's comment is alluding to, the hidden rise of technical debt for last mile problems and custom requirements.

Think we are dealing really with RAD vs traditional waterfall coding approaches. Both have ups and downs but the big drawdown is the stockholm syndrome effect that comes with relying on some other party for RAD.