Magento standard import is slow for all 8 years of Magento existence.
This is because the standard import is for stability and covering all the edge cases: for each transaction it runs a lot of business logic, checks, events, and so on.
There is an alternative Magmi importer for Magento 1.x which is faster because it operates on a lower logic level and skips a lot of business logic. Also, it has security vulnerabilities. Magmi is not compatible now with Magento 2.
I recommend the following:
- Use a powerful server with SSD and a lot of RAM for Magento import (and definitely do not use a virtual machibe for it).
- Create your own Magento extension for your particular import case. It would allow you to skip up to 90-95% of use cases the standard import need care of.