Disable non-relevant modules

All modules mentioned can indeed be removed from the project:

Actions UI - deprecated
Color - theme does not support colors
Help - nobody uses it (I guess)
RDF - removed from core, little value
Sitemap - there is no config + alternative Simple sitemap module is enabled & properly configured
System status - proprietary, seems like abandoned

Agreed, these can all be disabled.
Specific websites can reactivate them via config_split if needed, but I don't see a particular reason for that currently.