What I miss are 4GL. 90% of bussiness systems are some form of CRUD, or record keeping software. With Clipper/DBase III, etc you had systems up in no time, fast and with little non-functional bugs. And on the UI side you had keyboard shortcuts and forms that worked 100% of the time. Maybe some kind of browser based shell for running Harbour[1] apps.
Probably related to this slightly weird sentence at the beginning: "Some advanced 3GLs like Python, Ruby, and Perl combine some 4GL abilities within a general-purpose 3GL environment." I sorta get the argument but it's not standard usage. The problem is that there are (multiple categories of) language that are really post-3GL but 4GL was long ago coopted for a different purpose. And given different classes and branches of languages I'm not sure talking in generations makes sense any longer anyway.
I wouldn't say Microsoft/Access was the sole cause. Nantucket (who were eventually bought out by CA) and Ashton-Tate really missed the boat when it came to developing Windows versions of their flagship apps/tools.
You should have a read of "In Search of Stupidity"[0] and revel in the eye-watering commercial mistakes and foot shooting these companies indulged in during the late 80's to mid 90's.
From the mid 80's until around 1995-96 I used many of the tools written about in that book - WordStar, dBase, Clipper, then one day they were gone, largely because of incompetence and entrenched complacency.
I think Access was the start of it. But Microsoft's purchase of FoxPro is what really put the nails in the coffin. FoxPro had some shortcomings (e.g. Foundation Read) but it was incredibly productive and fast. And there was a Mac version early on.
It makes me sad to think of what FoxPro could have become. Microsoft didn't just kill the product, they pretty much killed the category.
[1] https://harbour.github.io/