Practically speaking, if you need to interchange files, you'd still need MS Office. But direct your grumbles at MS lock-in, not at LibreOffice.
Microsoft doesn't seem to be taking steps to lock
others out from editing Office format files.
I've had personal files becomes inaccessible before because they were in proprietary formats and the program no longer ran on my OS. That "lock-in" may or may not have been intentional by the software maker, but the effect on me was the same regardless. Now I use explicitly open formats and maintain my ability to change software.
Otherwise, pony up for Word so you can be on the standard as most business, or don't and just use a free online option like Google Docs. It'll do everything you actually need, anyway.