Maven Central is the place where the libraries are hosted, but not the place where they are found by users. Use Google/Stackoverflow/Reddit and simply search for what you want.
Searching for "command line argument parser java" immediately leads you to libraries and infact lists of libraries (see https://stackoverflow.com/a/7829772), of which most are going to be available on Maven Central.
Then you do your research that the library you are looking at looks valid and is trustable (!) by checking out the info available on it, maybe make another search to find opinions on it.
Then when you have decided to try it, look at its docs to find out where it s located on Maven Central and use it from there.
I think you're searching in the wrong place. The first search result for "argument parser maven" in google search yields this [1] - an ordered list of maven dependencies for "Command Line Parsers".
[1] https://mvnrepository.com/open-source/command-line-parsers
mvnrepository.com is good for what you are describing [1]. For example, searching for "command line" brings up the clear top favorite and tells you the number of usages:
The first thing I'm noticing is that there seems to be no way to judge the popularity of the libaries (an often-used proxy for quality, e.g. number of downloads, GitHub stars, etc).
I enter "argparse" and the first hit isn't even Java! It seems to be a npm package?? https://search.maven.org/artifact/org.webjars.npm/argparse
I enter "argument parser" and there are two hits. One with zero stars on Github and one with 1 star.
https://search.maven.org/artifact/com.github.easy-develop/ar...
https://search.maven.org/artifact/com.github.raphcal/argumen...
"command line" brings up another 0 star option: https://github.com/AlmondBranch/command-line-parser
I suppose the Java package ecosystem must be good if everyone says it is, but so far it looks to me like I'd find Maven Central very inefficient to discover high quality packages.