It isn't inherently something that needs to be SaaS. I could host the webfont on my own server, for example, if it were a legal option. But that isn't allowed,

It isn't inherently something that needs to be SaaS. I could host the webfont on my own server, for example, if it were a legal option. But that isn't allowed, so you're forced to load it off their servers. So yes it's a SaaS but only because the licensing forces it to be that way. I.e., it treats downloading the webfont into a user's browser as a copy and distribution of software. This is the bit that is ridiculous and needs to change. Print design for example labors under no such restrictions.