I guess you're being downvoted because of the swipe at JS, but that's pretty much what's happened yes. Desktop OS vendors dropped the ball on sandboxing and internet distribution of software so badly that we ended up evolving a document format to do it instead. The advantage being that because it never claimed to be an app platform features could be added almost arbitrarily slowly to ensure they were locked down really tight, and because of a pre-existing social expectation that documents (magazines, newspapers) contain adverts but apps don't. So ad money can fund sandboxing efforts and if it lags five years behind the unsandboxed versions, well, it's not like Microsoft or Apple are doing the work.
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.
It wouldn't even be so terrible, if it didn't tie us down to a crappy language (JS).