> This is valid even if Google's internal infra is strictly worse than what is available openly.

Indeed it is, because Sod's, Parkinson's and Wirth's laws.

> This is insane and a sign that something is deeply wrong in Google. Splitting Google up, forcing this infrastructure to become open, etc would be much healthier than perpetually killing small products to protect Google's secret sauce.

Given such a massive rewrite will not be possible without bankrupting the company, and such an open source would just amount to going non-profit (they would essentially lose all trade secrets and profit-making advantages), forcing a public domain of intellectual property, replacing the top executives without severance and stripping of for-profit status will be way better economically, than splitting it.