The point of ut is not to replace or invent new tooling. It is meant to be a set of tools that are simple, self exploratory and work out of the box with sane defaults. So, essentially, something that you don't have to remember syntax for or go through help/man pages everytime you want to use it.
Which BusyBox, toybox, and coreutils commands fail with data larger than RAM? Has that been part of the spec yet?
Just realized `LC_COLLATE=C sort` must be specified if you don't want it to ignore leading underscores in sorting due to LC_COLLATE=en_US.utf8 being the default these days.
If you can remember all of that off the top of your head and find it ergonomic to type out, then sure. But much like how I prefer someone else to do my content syncing as an ergonomic appliance rather than using FTP + curlftpfs + a VCS [1], I quite like this idea of a focused toolbox (written in a language that compiles to native code) and welcome it rather than having to store these massive snippets in my head (or write shell wrappers for them).
Yes it's easy to set up an alias or shell command or whatever, but that's besides the point :p