I disagree.
Given how the Constitution apportions Senate and House seats and how the Electoral College is constructed, the GOP has built in advantages - in the US, land matters more than number of citizens in terms of representation AND corporations are people, too.
It takes a Trump for the GOP to lose. Run Lady G, Little Marco, Brian Kemp, the Virginia governor who pretends he isn’t right-wing, etc. and the GOP wins.
I do agree that a principled, conservative GOP is dead. I doubt it has existed in my voting lifetime (1980). Remember, the sainted Ronald Reagan and his campaign back-channeled the Carter Administration to get Iran to release the hostages AFTER the election. Before Reagan was elected and his tax cuts passed, deficits mattered. Then, we have Inran-Contra. Let’s throw in a little Lee Atwater detailing what the Southern Strategy code words meant; he was on his deathbed looking for forgiveness.
The principled, conservative GOP is dead and cold.
The modern MAGA GOP is alive and well and a threat to take and hold the Oval Office, Senate, House, SCOTUS, and many (most) states for a good long while.