The market wants people to want "more features and faster execution." The market doesn't care what it's selling per se. If the web-browser-as-OS seems like an inevitability in that context, it's only a side-effect, and one that could change at any time.

WASM also impacts the labor market, as you mention. But it's not, as we might like to believe, because programmers' demands for more freedom and expressive power are being honored; it's because, as monkmartinez suggests [0] (and maybe this is what you mean by "floodgates"), companies would rather not be limited to a smaller human-resource pool when developing web properties.

If I sound a little dystopian, it might be because I'm currently reading Cyber-Marx [1], an insightful book from 1999 about the "information revolution" and its relation to capital.

[0] https://news.ycombinator.com/item?id=14342983

[1] http://www.press.uillinois.edu/books/catalog/66mwg3pc9780252...