I often wish Word from around 2000 back. Back then the software was straightforward and did what it was supposed to do without much fuzz. And the speed on modern hardware would be crazy.
The latest Word version does all kinds of weird stuff around formatting and numbering. I often get documents with messed up heading numbers or lists and I have no idea how to fix them. Nothing works.
I'd say that Office 97 was the pinnacle. I think you can still reasonably use it if you happen to have a copy.
This is of course problematic if you receive documents from other users :(
Try reading a 40+ page document with track changes enabled (and 100+ changes) - it pins a full CPU core for 5 seconds when you go to the next page!
It's essentially a giant XML file, so it's not going to win awards for speed or efficiency.
Modern hardware can parse XML with speeds measured in hundreds of megabytes per second.
On the plus side, it's nostalgic and reminds me of the old MS Word 6 on Windows 95 (or Windows 3.1?) so that's nice.l