Sorry, but running code you didn't write yourself is a fact of life to whose risk you will have to reconcile yourself, if you want to benefit from an extraordinary patrimony of code that no one person could write in a million years.
Just know that you're very much not alone :)
It's not just not thinking pragmatically, it's not thinking tout court. It's a thought-terminating cliché. It's trying to reduce problem X to universal solution Y because you don't trust yourself to genuinely think it through. It's the programming equivalent of Reddit neckbeards who regurgitate (semi-accurate) names of logical fallacies from Wikipedia rather than actually evaluating the other person's argument.
I think the supply chain concerns is real and important though.
In other words, there is a quantitative risk difference between depending on two external libraries (particularly if you pick well-vetted ones) vs. depending on 15000 libraries like some node projects.
Every additional library your build brings in, adds a small additional amount of supply chain risk.
So it's not about trying to be hardline about not depending on anything, but if you want to minimize risk you'd want to curate carefully which libraries you bring in.
Striving to reduce the number of dependencies is a good goal.
I don't think anyone here said it does.
Running a naive "cargo tree" on this project tells me I'm now also trusting about 80 other projects besides this persons project. Including a Wayland client? And a "Scoped Thread Local Storage" implementation? For a sysctl replacement?
It's almost as if "a sysctl replacement?!?" is necessarily built on an extremely complex edifice of code, due to how modern computers work, which can be hidden (cf: dynamic linking) but not avoided. ;)
(Less facetiously: Yes, if you start thinking through, from first principles, all the machine code which has to run in order for this tool to function on an acceptable range of computers, you can then start to grapple with the real problem, which is unfortunately more complex than "how many Rust crates does `cargo tree` output?".)