No true scotsman fallacy?
I entirely understand what you mean, if you use a textbook definition they are certainly not conserving anything.
But they call themselves conservatives, others call them conservatives, and as far as anybody is concerned, that is what being a 'conservative' is about now.
'Actual' conservatives need to give themselves a new name to detract from the shitty politics of the nu-conservatives.
No, 'scotsman' is an ethnicity, 'Conservative' is an ideological movement. In order to be a member of the movement, you need to adhere to the principles of said movement, or at least strive to.
In America, that ideological movement is 'Conserving the founding values of the nature. The movement was shaped/forged by Ronald Reagan, Rush Limbaugh, Will Rogers, and a fair number of others, but those are generally the standard-bearers.
An argument can be made that once a movement has been sufficiently hijacked by people who claim the name but don't act on the ideology, a new name is needed. The thing is, the establishment hacks do
not dominate the movement, the 'country club Republicans' have
always been around, have
always been embarrassed to share the Republican party with actual conservatives.
Just because a bunch of long-time leftists and young millenials/zoomers catching up with politics now are disgusted with the parasites latched onto the movement,
doesn't mean that it's time to play the post-modern leftist game and start redefining words.
This has been a problem since the 80's at least. Just because it still exists now doesn't mean we're going to give up the term.