Others have brought up the Office 97 style for good reason. Everything has an icon, on an icon toolbar. Every command can also be on a file menu but most of them there don’t have an icon. The ones that do are special or intended to draw your attention.

And there’s a consistent metaphor: for example the web browser is represented by a globe for the world wide web. So the “hyperlink” function is a globe with a chain. This the “preview as web page” is a globe with a magnifying glass (whereas the print preview command is a sheet of paper with a magnifying glass.).

This icon language hints at function through its form and helps serve as a cue, a reminder, or a visual representation of its function.

And it all worked on 640x480 256 color screens. They are thoughtful and useful. These plain flat uninformative icons are just rude.

Sure. There are also icons that are plain flat and don't use metaphor and work great. Play, share, hamburger, bluetooth, power... i am sure there are more. Icons are more about familiarity than anything.

I assume you were very familiar with Office 97. I can tell you people born in 97 are probably not. High chance they might not like and understand the icons because they aren't familiar with them.

It's like when everybody wants to design logo as unforgettable as Nike. But in reality anything people see 20 times a day people will remember.