Actually CPAN modules are already ranked - by how often they are mentioned on PM for a start. Popular modules are simply, more popular. That doesn't mean that they are best, for some value of best, just that they are more popular.

That is good news for someone looking to solve a problem. Popular choices are often easy to find out about and once found are easy to get information about. It's bad news for new modules that may do a better job than the current popular module for the job but haven't yet reached user critical mass - i.e., become popular.

Having a cohesive section that lists the popular modules and a discussion of each module allows the best of both if the discussion can provide links to up and coming solutions to the same problem the module under discussion solves.

You never know, with such a section Data::Dump::Streamer may even become more popular than Data::Dumper.