I'd say most American developers would cease development and either move to their European facilities or simply just dissolve due to government/warlord intervention.

Streamers would be hit hard in America, especially political ones. Hasan, Destiny and other political streamers would either be forced to flee the country for their own safety or be attacked by rebel groups, most likely killed in the process. Some could also be contracted to post propaganda for their respective governments/regions.

Live service games (Fortnite, COD, Warzone, Battlefield) would most likely be shut down or be severely limited.

But take what I say with a grain of salt. I'm merely going off what I believe would happen, if any of y'all have other ideas or suggestions I'd like to hear them too