> HN consensus seems to have changed from Google being an unstoppable monopoly to being unable to sustain its business model.

The contradiction is resolved once you recognize that advertising is not productive labor, unlike food distribution. Nobody can beat Google at what they do, but there's ultimately not a sustainable organic need for what they're selling.

I don't think many tech companies are attractive targets for nationalization for this reason.

> There's plenty of negative historical experience with nationalization.

In immature, geopolitically vulnerable economies, often during times of general upheaval. A targeted, degenerative process that is properly incentivized would be different. A "finish line" where getting bought out would be a desirable outcome for most involved.