> order of magnitude

It is much worse than that. Even taking the node names at face value[1] that is just one dimension, there are two/three[2] dimensions to consider so it would be 100x different.

Nehalem(2008) was a 45nm node based chip and had ~3MTr/mm2 transistors in comparison today we have 3nm(N3E/P/X/C) nodes(2023-4) from TSMC area about 220MTr/mm2.

Of course that is just one metric- transistor count, there are many other improvements to consider over the last two decades.

[1] Processor node names after all haven't been tied to physical scale for 30 years https://www.eejournal.com/article/no-more-nanometers

[2] HBM that modern GPUs use already leverage 3D ICs.