Mathematica uses Intel's Math Kernel Library (MKL). Intel puts a lot of work into optimizing the MKL for Intel processors. It's unclear whether it puts in the same effort for rival CPUs. Years ago, it seemed clear that it didn't. Here's a recent blog post reporting some plusses and minuses:
https://danieldk.eu/Intel-MKL-on-AMD-Zen
Unfortunately, I am not an expert on such low-level computing issues, and I have little confidence in judging whether a source is reliable. There is also the issue of which version of MKL Wolfram uses. I don't know the differences between versions of MKL, so I cannot comment further.
This post compares the built-in benchmarking across various computers (for V13 in April 2022):
https://mathematica.stackexchange.com/questions/267262/benchmarking-mathematica-13-across-machines
Anton Antonov posted a method for reading in all the answers and extracting a Dataset[] of the data here:
https://mathematica.stackexchange.com/questions/235390/how-can-i-ingest-and-analyze-benchmark-results-posted-at-mse/235392#235392
Someone asked a similar question about V12.2. No one has asked about V14 yet.
