You're going out of your way to paint Google's arguments in the worst, malicious light. Their interest in caching is not to save their own bandwidth costs, but

You're going out of your way to paint Google's arguments in the worst, malicious light. Their interest in caching is not to save their own bandwidth costs, but to lower costs and load times for users. Google's efforts in the web performance space are well documented (see lighthouse as one example). The reasoning for "only the latest version" also happens to be the only one that makes sense: having multiple versions of each font drastically reduces the ability of browsers and CDNs to cache, quite obviously. The motive you ascribe to google, namely user tracking, has absolutely no logical connection to the "latest version only" practice: Google's ability to track users would actually be enhanced by versioning, because their servers are only ever contacted for uncached resources.