High profit software products have monopoly pricing power from network affects: everyone uses office for compatibility/familiarity with what everyone else uses, everyone uses Facebook because everyone else does, everyone buys advertising buys from Google because that's who everyone sells to because that's who everyone buys from.

No one has shown a network effect for models yet. Models are commodities. Anthropic etc will make the sort of profits one makes selling commodity goods (a couple of percent), plus a perhaps a bit of extra margin from being a few months ahead of open weight models (if that profit can justify the billions in training costs).

I do agree that local models are irrelevant. But local inference and open weights are different things. You can go on openrouter and see that there are dozens of companies selling open weight inference.