I WORK at Microsoft 365 (not on Word), and it's actually good LibreOffice can read old Word files even if Word can't. I wasn't even born until 1997, tho when I was young I played a lot with MS-DOS and Win9x, since my toys were old PCs.

The reality is, both MS Office and LibreOffice are legacy messes. In the 90s MS aggressively broke compatibility to get users to upgrade, which is why LO can read it. Now MS is excellent at compatibility, because the focus is subscription software your employer pays for.