the “X-bit” marker is essentially dead,

That was kind of the point, it's ridiculous to think a modern CPU hasn't evolved dramatically since the introduction of mainstream 64 bit in 2003.
It's still called 64 bit, but there are so many developments.

for most people, who just care about “IPC”

Exactly, and that is achieved by a modern core operating at about 256 bit internally, to achieve faster execution.

I'm not arguing it's wrong to call it 64 bit, because there is no "true" bit width to call it. So we might as well still call it 64 bit, because it describes the core instruction set. (not just pointers as was claimed by someone else) My point was just that it doesn't really describe the dramatic development of the CPU as a whole, and even the individual cores are more complex in hardware, despite the main instruction set remains the same.