Does that mean there’s not an actual, realized loss?

I think it's more like the construction contractors game. Example, was figured to make $10,000 on project but only made $9,999 so the project lost money.

Yes, the world generally works better if everyone is making money

Nvidia?

It is highly unlikely that companies will decrease dividends paid due to the recent market downturn unless it is sustained for a long period. Stock value may be down but that is only important when you sell. Hold on and ride it out. The only people that are really affected at this point are those about to retire and who want to change their investments to better align with retirement. For everyone else this is a buy opportunity IMO.