I think the real reason the web was built was because Google, etc... Decided they need a distribution platform that could not be locked by OS vendors, as that would be a theat to their business.
That's a cynical take. DHTML predates Google. Demand was already there before the giants appeared.
What really happened was that developers figured out that the deployment story via web was massively simpler and less burdensome. Producing good installers was hard, people in offices often couldn't install anything, and then you had to deal with DLL Hell... whereas the browser was always there already. So a series of unfortunate events was set in motion that ended up with what we have today.
