Why didn't something better come along in the 90's or 2000's or 2010's that made them less appealing or obsolete? That something could be installed "everywhere" by now.

Not to say there hasn't been progress of course -- I think say fish, ninja, jq, etc. are great projects. They also are installed in most places, and ninja and jq aren't that old.

IMO, it's just a lot less than you would expect given the huge growth in computing in the last 20-30 years.

From my experience with of them: They are good enough. Leapfrogging software with incremental advances only works sometimes and the "standard env" is already very advanced.

I do appreciate the features provided by, e.g., ripgrep over GNU grep but I can likely get the job done without it.

There are ofc some exceptions, like jq for JSON handling, but I have only really seen that used by developers. However I've rarely seen it on legacy/ production machines because it often makes more sense to use Python/ Perl at this stage.