The web today is a much more capable ecosystem than "HTML5" was for the original iPhone, and while many web developers crinkle their projects into minified source or opaque WASM blobs, every user has browser developer tools at their fingertips for peeking behind the curtain and making changes live.
It is perhaps most surprising that in the post-Flash world no comparable development environments have sprung up to replace its end-to-end animation and interactivity workflow. Game "engines" like Unity and Godot have captured much of the game development audience for Flash, but their ability to produce web exports is clearly an afterthought, producing huge files, glacial load times, and often simply crashing in any browser that isn't a bleeding-edge instance of Chrome.