> I guess preferential treatment could be the only issue?

I'm not sure it's the only issue, but for now focusing only on this issue: it's a really big issue. The R's often complained about Dems choosing winners and losers (IIRC related to the solar industry). This is now way beyond what the Dems were trying to do by advancing solar. The gov can use it's buying power to sway things towards Intel, for example, over AMD. Huge potential for conflict of interest that will distort the markets.

The other tangential issue is that in some cases these can look like bribes. For example, OpenAI "offering" 5% of their stock to the gov.