Take ls: like the article says gnu ls has tons of options to configure how its output is displayed. But that's because ls is a user interface for displaying lists of files. I'm not sure how the proponents of all these new shell keep missing this point. If you just want a list of files in a POSIX shell you use a glob expression.
But whatever, nushell has its own builtin ls that is for getting lists of files. And then you pipe it into other commands to configure the output. Great. Can I get the output to be like 'ls -C'? Nope. Can I turn off colors? No. Can I add the indicator character like 'ls -F'? Not a chance.
Well, at least I don't have to pass '-l' just to see the file mode... actually I do, otherwise it would be too slow.
Many of the options that clutter gnu ls are generic options that apply to all tables, and it would be nice to abstract them. But many aren't, many are specific to what ls is doing and it's hard to me to see how this all could be generalized in a way that applies both to ls and to grep.
For now nushell sidesteps the problem by not having its own reimplementation of grep, unlike ls if you type grep you get real grep and you can't pipe the output into anything meaningful.
The best I could do to replicate grep inside nushell was this:
cat haystack | split row -r '\n' | enumerate | where item =~ needle
The cop-out solution to this is to have builtins return objects (as in OOP objects, with methods), but then everything needs to be written in the same language.