[Someone]

> because it is essentially the hosting that they are providing as a product

That would be true _if_ they were forced to open source all their code, but it isn’t today.

> Even if, say, google open sources its whole search infrastructure, it does not at all means you can just host your own due to the huge hardware requirements

You can’t but Acme Inc and other bigcorps could, and Google’s margins would evaporate overnight.

[smgpie]

Well, chromium the web engine is open source but it is still hard to craft a web engine with equal level of performance and other metrics, even with a team of talents.

Besides that, what you say may be true from the google's perspective. From a user(which I am) perspective, Google and Microsoft and other big corps have proven again and again with their actions that they cannot be trusted, just refer to https://www.gnu.org/proprietary/proprietary.html.