Oh yes, i do know that.
but do YOU know how they looked back then? because they're literally just toolbars with buttons on em and canvas frames which are just fricking images / application logic! rendering these viewports/canvases are challenging for sure -- back then just like today, because thats where where the domain logic goes.
the UI back then were fucking trivial, youre deluding yourself if you think anything else.
Lets go through your first examples one-by-one, as the theme continues i will stop at some point.
* Word: literally just 1 menu/text, 2 rows of icons. And a range picker. you can do that within ~15 minutes even as a beginner.
https://winworldpc.com/res/img/screenshots/97-98-11f3805bab5...
* Excel: same as word, with the addition of a grid in the body. the challenge is in chaining together the cells. trivial as hell -- as long as you ignore the application/domain logic, which would've been just as complicated back then.
https://winworldpc.com/res/img/screenshots/57db2161e19c9e95d...
* slightly challenging for someone that hasn't encountered flex. extremely easy -- albeit time consuming just because of the quantity of buttons. still doable within https://www.webdesignmuseum.org/uploaded/old-software/graphi...
* logic: once again, the challenge is in the domain. the UI itself is just buttons in rows. trivially done by simple flex rows.
https://www.muzines.co.uk/images_mag/articles/mt/MT_93_04_no...
* winamp 2.5: once again, trivial to do. creating this UI -- without the domain logic of actually playing the music etc behind it -- can be done within https://preterhuman.net/software/wp-content/uploads/2018/08/...
It goes on and on. Every single example youre citing is just rows and rows of icons.
Thats extremely easy to implement with pure html and trivial css.
give any of these UIs to an experienced frontend dev and they'll provide you with a click dummy within 15 minutes to 3hours, depending on the quantity of elements on it.
I'd be pointless, precisely because nobody cares about such trivial UIs anymore... But hey, whatever floats your boat, right?
And everything I wrote here is ignoring the fact that every one of your example was the opposite of easy back in the 90s. They were developed by whole teams over years to get to that point, despite what was claimed initially. And duplicating this with html5 is trivial, that itself should tell you how much easier it's gotten if you just don't chase the hippest tech that's fotm right now