They did indeed host quite a lot of stuff, and it was undeniably popular as a place to get your binaries hosted free of charge.
But at the same time, is it being used as a source code repository? A lot of those projects don't show the CVS/SVN features. And sourceforge never hosted the biggest and most established projects, Linux and Gnu and PHP and Java and Qt and Perl and Python were all doing their own thing. And pretty much every project visible on that page had its own separate website, very few projects hosted on sourceforge exclusively.
SourceForge was the upstream source of truth for a huge percentage of small apps bundled by various distros (and BSD ports etc). Even when the upstream maintainers just uploaded the latest tarball to SF and didn't use their hosted VCS, just the hosting was a major boon to all of the tiny teams and individual maintainers of FOSS projects.
They did indeed host quite a lot of stuff, and it was undeniably popular as a place to get your binaries hosted free of charge.
But at the same time, is it being used as a source code repository? A lot of those projects don't show the CVS/SVN features. And sourceforge never hosted the biggest and most established projects, Linux and Gnu and PHP and Java and Qt and Perl and Python were all doing their own thing. And pretty much every project visible on that page had its own separate website, very few projects hosted on sourceforge exclusively.