The search engine on the rubygems.org web site lacks flexibility. You cannot pick a parameter for sorting, and you cannot specify parameters (such as the name or the gem description) for targeting your search. This makes it impossible to effectively filter the gem list.
On the other hand, this site offers far more flexibility. You can search Ruby gems by name, by description, or by other parameters. You can sort the results by number of downloads or by other parameters. Sorting by number of downloads allows you to see which of the gems in your search are the most popular. This helps you pick the better-known gems. If you're looking for a project to contribute to, sorting by the number of downloads will lead you to the projects that have a greater impact on the Ruby community.
I fully intend to do this. However, it can take many months for changes to be approved. On the other hand, I did not need any approval to roll out this site. Furthermore, this site's search engine can be a proof of concept for the rubygems.org web site.
The Rails source code for this site is at https://github.com/jhsu802701/rubygemsearch. The data is provided by my Ruby gem called gem_scraper. The source code of gem_scraper is at https://github.com/jhsu802701/rubygemsearch.