Enabling custom scripts inside the SP admin center will affect non-personal & non-self-service sites

I start working on a root site collection for a new tenant, and inside classic pages, i found that i can not add  scripts editor web parts. I know that i can enable custom scripting from SP admin center, so i enable it as follow:-

but the 2 options we have are related to personal sites and self-service sites. but when i enable these options (as shown above), it also enable it for the root site collection (which can not be considered as personal site or as a self-service site)... so can anyone advice on this?

second question. As I know that personal sites are the onedrive online sites for each user and that the self-service sites are site collections which end users can create from their sharepoint home page.. so is this correct? or the personal sites and self-service sites inside the above setting are targeted to something else, so it affected the root site collection as well?