“Losing?” No.

“Throwing away any chance of?” Yes.

The US is desperately clinging to oil while Solar is cheaper and better. If the US truly wanted to have green energy, they would buy cheap solar from the PRC.

The US is VERY individualistic...most of the time.

In my local area, one in three houses have some sort of solar. Some have massive batteries. And more are getting solar per day. Ive heard of 0$ bills from PGE where its .50c per kwh. Owners themselves are jumping in on the energy technology.

What I believe we will have is:

Some areas of the US will have extremely good and resilient power grid options. Probably sections of California.
Some areas will not have ANY resiliency (Texas/etc...)
Most areas will have mediocre investments in the power grid.

Im a layman, but I do see a lot of people investing. So dont count them out.

Did the US ever have an advantage on energy? I thought that they never massively invested in nuclear nor renewable and that the electric grid(s) is(are) a mess with lack of interconnection and frequent blackout (relative to other first world nations)

Mass electrification of end uses, with nuclear for clean firm baseload, and wind and solar plus storage for peaks, is the future of energy. The longer the US is unwilling to let go of fossil fuels, the further behind it will be. China already has enough of an advantage that it has secured its position as the global leader of energy technology for at least the next century.

The minute the meta was no longer burning Dino goop we lost the advantage.

You could've stopped at "advantage". Nothing that comes after would change the answer.