This is actually a relatively new "feature" of web browsers. When I was a kid, if a page didn't load completely it would just make do with whatever assets it could grab. Images would be replaced with a stand-in icon and some descriptive text.
4realz are you serious? What is the actual downside of that? As a kid, it made perfect sense to me, and I often would right click the image and press reload or just refresh the whole page. Now whenever images don't load (which is often these days, since cloudfare blocks tor 90% of the time until you load the image in a separate window and fill out their captcha, and even without tor, wireless networks tend to be extremely unreliable), it's not easy to tell whether the page is broken, since it just collapses the spaces where the images would have been.
Further, if you directly view an image and it breaks half way, the browser will hide it and say it's corrupt (and have no "show anyway" button), unless the size wasn't provided, then the browser just thinks it's valid, despite that it could parse the JPEG file and find out that lines of pixels are missing. Calling either of these cases a feature seems very biased.
We aren't even talking about one of the worse problems, which is when a page fails to load, the browser doesn't try to reload it - you have to come back and press reload yourself. I've wasted literally hundreds of hours doing this.
It's the cost of it working at all, at least in terms of it being as accessible as it is:
Making it feasible for people to create websites quickly enough to be worthwhile entailed allowing the tag soup non-standard HTML we see in practice now, and the confluence of desire and technical limitations made plug-ins inevitable.
A "better-regulated" Internet wouldn't have had the Web at all. Remember that, according to the people using it circa 1988, file transfer and hypertext were both solved problems, with FTP and Gopher respectively already in existence. Unstructured hypertext, something Gopher was not really designed for, wasn't especially desired until some random at CERN released WorldWideWeb and httpd to the world.
