None of the "replacements" interest me. When I try the "new" ones I cannot get interested in them either. When trying new programs I am looking for whether a program can do something essential that I cannot do myself, e.g., with shell scripts. However I am beginning to think another reason is that these "new" utilities are consitently too complicated, e.g., too many options. It often seems as if the authors are trying to show off their programming skills with some new language they are trying to learn, e.g., Go or Rust. Comparing these new programs to original UNIX utilities, many (most) of the UNIX ones seem comparatively simpler.
I write quick and dirty single-purpose utilities for myself because I want relatively simple programs. I try to keep program size reasonably small so I use C not Go or Rust. I avoid creating options. FWIW, seems like that was true of most of djb's utilties, too. Some of the best "new" UNIX utilities I have seen have come from from people who use djb's C functions and/or copy his programming style, including the preference for small program size and few-to-no options. For example, the authors of runit or s6 have some interesting utilities. The author of tinysshd has some useful ones as well. These projects are generally not popular but they are generally high quality, IMHO.
There are some JSON utilities listed on this blog page. Despite so many options for libraries and programs to process JSON, I still cannot find one that does something very simple: 1. extract JSON from HTML, 2. print it in a customised, human-readable, left-justified format that 3. makes it easy to process further with other programs. Hence I wrote a stupid program for myself that extracts JSON, prints the keys and values left-justified, making it easy for me to read with less(1) and to process with traditional UNIX text-processing utilities. (I am probably mistaken but I believe the one I wrote may be able to operate at the same speed regardless of the size of the JSON data. This needs to be tested.)
I have written several shell scripts over the years that have a subset of the functionality of fzf (or a superset of urlview's, which came much earlier), namely finding and selecting items from lists. I am still not a fzf convert because generally it does not do anything essential I cannot already do myself. Plus it is larger, more complex and generally slower.
Someone once said the best interface is no interface. For me, the less required user-interaction (including selecting options), the more powerful the utility.