No more than any other western country usually being dominated more by one side than the other.
At the moment, the Republicans are still the dominant party at the state level, so the fact that democrats hold an extremely narrow trifecta federally doesn't really mean that much.
DC/PC statehood will only diminish the GOP's advantage in the senate, but they will still hold the advantage.
Packing the SC won't happen.
The GOP has a rough road ahead but a LOT can happen in 4 years or 8 years. Also, never underestimate democrats complacency and ability to lose elections they have no business losing.
Imagine how bad Democrats would be right now if Biden actually ran and won in 2016. By 1993, the Republicans were wiped out downballot.