If we accept that the “web of apps” and “web of documents” are two separate things, and that the development and maintenance of the browsers for the “web of apps” is essentially left in corporate hands, what is left is the question: how expensive is it to develop and maintain the browsers for the “web of documents” ?
And I suspect that the answer is “much less” (than the “web of apps”).
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For starters, most of what the #WHATWG is working on is largely irrelevant for the “web of documents”. This means largely no development efforts to “run after the latest revision of the spec”. I would expect most of the work to be of the maintenance kind (fixing bugs, security issues, and the like), which is sadly the kind of brutal, unglamorous work nobody wants to do.
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