I think you can compare modern chess programs with each other to evaluate this.
Some comparisons have been made between different modern chess engines in TCEC.
Stockfish is particularly well adapted to using lots of cores. i.e. Stockfish has a much larger advantage over the other modern programs when lots of CPU cores a available as they have optimized hash table contention very well.
If you compare NNUE stockfish to classic stockfish is also the question of how much strength stockfish NNUE loses when playing on hardware that does not support SIMD.
Similarly you can look at compare Leela Chess with and without GPU.
On the old vs new:
Old chess engines will have been optimized to use much less memory, where as modern chess engines use a very large hash table.
i.e. 3. Software that is better-adapted to new, bigger computers. is quite a large component.
I’m pretty interested in understanding the size of this effect by scaling down the memory use as well as compute to historical levels. (This is one of my concerns about hippke’s experiment, though it seems like they think it’s not a big factor.)