My experience is actually the opposite.

In the old days there was no expection when and if users would upgrade anything, so vendors had to take extra care to ensure compatibility or they would lose business. People in a single office could be running 6 different versions of Microsoft Office, and the same file had to be viewable and editable on all of them. A company could decide to upgrade to Office 2010 but stay on Windows XP, so the Office division had the finanical incentive to ensure that newer versions would work on an older OS.

Nowadays the standard is "you must be on the newest version of everything all the time, or the app won't work". Don't want to upgrade to Win 11? Want to use Firefox instead of Chrome? Don't want all the bells and whistles that come with the newest version of the software? Too bad.

SaaS has that potential but the reality is more often that the vendor gets acquired, or they just decide to stop supporting it, and shut it down. You have no options to keep running what you had, only to migrate to a replacement, which is likely another SaaS which will do the same thing.

Or, as in the case of Microsoft Publisher, announce that it will be going away on a certain date with no recourse.

Before 10/26 I have to re-work my desk position manual and a deposit sheet which use Publisher and which MS Word is _not_ suited for. Probably will do them in LyX or LaTeX.