Internal links aren't getting aliased When saving an internal link to content (within the wysiwyg editor), the paths don't get aliased like they do with D7.

If I have a node (at path /node/10), with an alias of /some/other/path, when that page gets saved, then cached/viewed, the link that gets generated for the user is /node/10.

This has several drawbacks, not the least of which is that we have our breadcrumbs reliant on the URL path.

I've looked at all the input filters on the appropriate text format, but there's nothing there for it. This seems like kind of a huge issue for Drupal, I'm hoping that the fact that I can't seem to find anything on the issue means I just have a config wrong somewhere.
Drupal 7 doesn't do anything like that in core. You likely used another module. Pathologic provides this, also exists as a D8 version, only as a dev version, though.