For what was until a few days ago the largest public company in the US, that doesn't sound unusual?

Still interesting to have concrete numbers on the phenomenon, I’d say.

Doesn't it? I would not expect the largest public companies to be the most active venture capitalists. The other 10 most active funders are all specialist investors, not standalone companies with venture arms. You have to go down to about #15 to find the next corporate investor, and it's not Microsoft or Apple or Saudi Aramco, but relative minnow Salesforce.