Also, to be fair to your argument, Composer will load packages from outside Packagist, and VCS systems other than git, so the actual universe of available routers is probably much, much bigger. I'd suggest this as another example of how not conforming to a standard (Packagist as the de facto PHP repository) is a benefit. You don't even have to care about Packagist and Composer still works just fine.
Composer makes dependencies flat , and PHP isn't module based,but namespace and class based.
Which makes libraries way more stable,unlike the nodejs galaxy of packages for instance.
And by the way,most of the packages listed aren't routers.
If you only search the word "router",you'll get only 21 pages,roughly 300 packages.
now go on npm.org and type in router you'll get more than 1600 packages.
Where do you think the problem is ? is nodejs a module based language with dependency trees , or PHP , class and namespace based language with flat dependencies?
92 pages of the same basic router implementation. That is a problem. A huge problem.