Purpose of protossl outside of htaccess?

I see in .htaccess that the protossl variable is set. And from the comments in that file I see how it is used to keep requests http or https.

But take the case where your website is fully https.
If you rewrote (hard coded) the redirection code to specifically state https (instead of inserting that info via the variable), would there be any need to set the protossl variable at all? Couldn’t it be removed from .htaccess all together?

I guess my real question is, is setting the protossl variable in .htaccess only used in .htaccess?
Or is this variable somehow carried over into Drupal and used as a variable for some of it’s tasks (like creating URLs’ for css or js files and such)?

Drupal version: 

Source: https://www.drupal.org/taxonomy/term/22/feed