In my experience, the newest features (I mean those introduced in the last 20 years or so) while nice (and in a very few cases actually useful and used) are any

In my experience, the newest features (I mean those introduced in the last 20 years or so) while nice (and in a very few cases actually useful and used) are anyway "marginal" to most (like 80-90%) Microsoft Office users. What Office (particularly Word and Excel) can do is usually several times (like 10x or 100x) what the normal, common, user actually needs or knows how to do. In every normal office there are maybe 1 or 2 people that are "MS Office experts", all the other people use some pre-made template or use Excel and Word as some evoluted form of Calculator+Notepad.