Though it is worth noting that there was heavy competition in the browser space prior to the specs we have today. Part of the reason we ended up with a heavily spec-driven web is precisely because the high level of competition was leading to claims of corporate espionage, and it was expected that end user experience would be better with standards.
I absolutely agree the end user experience is better. I disagree that has anything to do with competition.
One manufacturer would call all the shots for the _one browser_.
There would be zero competition until something calamitous happened to the manufacturer and the pendulum swung to a new monopolist.
We even have an example of how this plays out to fall back on; Macromedia Flash.
If we needed to support another browser we'd need to provide a new solution built to its specification.
Open standards have allowed the possibility of multiple browser vendors, without making the life of browser consumers (i.e. developers and organisations providing apps and sites) a living hell.
Without this, we'd be providing apps and sites for a proprietary system (e.g. Macromedia Flash back in ancient history).
Furthermore, when Flash had cornered a market, it had absolutely no competition at all. A complete monopoly on that segment of the market.
It took Steve Jobs and Apple to destroy it, but that's a different story.
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The reasoning for only three engines, isn't the fault of open standards.
There are many elements of our economic system that prevent competition. Open standards is not one of them.
We had a web before open standards. It wasn't the best user experience and each browser was somewhat of a walled garden, but there was heavy competition in the space.
I imagine there's most likely a subset of the population who believe that open standards are aligned conceptually to regulation, and that any form of regulation in a free market is wrong.
This subset of the population is misguided at best, and delusional at worst.
Open standards are essential.