Why does a Flutter web app's initial loading performance genuinely require particular careful attention, given that it needs to actually download and properly initialize the Dart runtime before your app's own actual content can even begin to display at all?

Unlike a genuinely traditional website that can typically display at least some meaningful basic content almost instantly, a Flutter web app first needs to actually download its own compiled JavaScript or WebAssembly bundle along with the underlying Flutter engine itself before your app's own actual content can even genuinely begin to properly display anything meaningful at all, which means the very first initial load can potentially feel noticeably slower compared to a considerably simpler, more traditional website, and properly optimizing this specific initial load experience, such as by displaying a genuinely well designed loading indicator during that unavoidable initial download and startup period, meaningfully helps improve the overall perceived performance for a first time visiting user.

<!-- Adding a genuinely custom loading indicator directly within index.html -->
<div id="loading">Loading your app...</div>