Yes, hooks are made to extend MediaWiki functionality as extensions are for, extension writers use them (as do users) to extend what is normally possible in MediaWiki out of the box. If you don't want to do something more than is possible out of the box with MediaWiki, then hooks/extending are probably not for you. Can I ask why you are adverse to extensions? Mediawiki comes bundled with many extensions that are fairly necessary to do a lot of useful things... such as parser functions to do math and calculate things to help create advanced infoboxes etc. Inputboxes, and lots of other extensions. Especially the WikiEditor extension that provides the editing toolbar when editing. Unless you enabled none of them on install, you probably already have extensions running.
It would be nice if there was a footer page to edit like there is for the sidebar, but unfortunately there isn't. Extending either through an extension (that uses hooks) or through a simple user-written hook would be required.