Or tried to use Microsoft Equation more than a couple of times inside a single document. The thing was ridiculously prone to crashing on top of producing butt-ugly typesetting.
Of course, that falls under “using OLE”, but IIRC so does using WordArt, which was rock solid (albeit much simpler and in particular incapable of in-place editing).
I remember a long, long time ago firing up Access. I quickly closed it and continued to use Excel as a database. As it was only for personal use this wasn't an issue.
I hated Access and eventually abandoned it. Meanwhile, I pretty quickly decided that Excel is the fastest and overall best Microsoft product by a mile. I now just use Google Sheets, but if you have Windows and need to do lots of spreadsheeting, Excel is just by far the way to go. Far, far better than Libre Office, Numbers, or Google Sheets.
To be fair, I was rarely dealing with more than a couple thousand rows. If it were millions, and complicated joins, maybe Access (or probably SQLite) would be better, but oh my god, how is Excel so much faster and more polished than everything else? (Rhetorical question: Joel on Software has some stories that help answer.)
Pre-web I used it for internal process automation - it required less effort than anything else (including modern capable frameworks like Rails) to provide a lot of functionality to applications with a low number of concurrent users (1-20 users).
I do really miss that - this kind of app is now often implemented with a low-code platform (with expensive consultants) or a web framework (5-10x the effort required for the same results).
Earlier and later versions were worse, and Outlook was horrible if you were stuck on a domain.
Excel always had issues if you were doing something stupid like using it as a database and all of the apps had issues if you were being stupid with OLE via copy/paste or were using Internet Explorer.