That's very different from "comparing it against a one-year old version.
The outcome of Apple not keeping their page up to date is that they were misleading the user by comparing Safari to a version of Chrome that is no longer current, or relevant. The action (or inaction strictly speaking) might be different, but the result is the same.
Apple have enough staff that they could keep a page up to date if they wanted to. They chose not to.
> misleading the user by comparing Safari to a version of Chrome that is no longer current, or relevant
If they had continued to update the version of Safari in their comparisons without updating the version of Chrome I agree that would be misleading. But leaving the comparison frozen because they haven't updated their page is just the normal difficulty of keeping things up-to-date.
(Disclosure: I work at Google, speaking only for myself)
Multiple updates for Safari are delivered over the course of six months. And note that the graph I've shown you plots the daily performance of browsers for the past year.
I agree with you that there was nothing wrong with Apple posting a page after a Safari release, comparing it with the Chrome version at the time, and then not updating the page until their next significant Safari release.
However, it is true that Safari gets feature updates much less frequently than Chrome or Firefox. Historically, there's the integer update in the fall (13 to 14 to 15) followed by the .1 update in the spring. Those are when features are added. The Safari updates that happen in-between are only bugfixes; some bugfixes may have performance implications but they don't include improvements to language support (HTML, CSS, JavaScript).
Safari 15.1 is already out but I think they only used that version number because it includes a significant UI change (to tabs), it's not an indication that they're moving to a faster release cadence for features.
The outcome of Apple not keeping their page up to date is that they were misleading the user by comparing Safari to a version of Chrome that is no longer current, or relevant. The action (or inaction strictly speaking) might be different, but the result is the same.
Apple have enough staff that they could keep a page up to date if they wanted to. They chose not to.