That's very true! Although, I don't think it used to be true; there used to be several different, incompatible font systems. There were many simple bitmap-font formats for operating systems/display protocols (Windows, MacOS, and X11 all had their own); and then there were more complex, vector font formats, originally designed for printers to use internally, but then extended to computers through desktop-publishing software (e.g. Adobe Type1, Apple TrueType.)
If you think about it, much of the original point of desktop-publishing software, back when OSes could only natively use bitmap fonts, was that desktop-publishing software could do WYSIWYG layout and preview-rendering for vector-font "instructions" (e.g. PostScript.) Fonts were indeed a lot like VSTs!
If you think about it, much of the original point of desktop-publishing software, back when OSes could only natively use bitmap fonts, was that desktop-publishing software could do WYSIWYG layout and preview-rendering for vector-font "instructions" (e.g. PostScript.) Fonts were indeed a lot like VSTs!