Compare the HP EX920 (1TB for $300 on sale) to the SSD in the... 15" MBP 2017, or something.
HP EX920: http://www.legitreviews.com/wp-content/uploads/2018/04/hp-ex...
Apple: https://www.notebookcheck.net/fileadmin/Notebooks/Apple/MacB...
Same AS SSD benchmark.
Now you can argue that since SSD performance increases with size, maybe that's why. Then prove it.