Based on the https://devdocs.prestashop.com/1.7/themes/getting-started/setting-up-your-local-environment/
it seems that Start Theme is still the recommended way. However, Starter theme is deprecated. I am still confused about which theme to use for a start
EDIT:
It is Classic theme with dev tools in it.
https://github.com/PrestaShop/PrestaShop/tree/develop/themes/classic