Idk, I'm in my mid 30's and I've never had a moment where I've been glad to see something on SourceForge.
For whatever it's worth, which is probably not much, I'm in my late 40s and I never really liked sourceforge either. Too many clicks to do anything (still true), and I didn't like cvs (also still true, but thankfully now irrelevant).
(My SF account dates from June 2004. I expect I was thinking about using it as version control for a FOSS project I was working on at the time, though I don't know why, as it seems SF didn't support svn until 2005. Maybe I couldn't find any better options? The pre-GitHub ecosystem was pretty bad! But, luckily, I ended up not having time for any FOSS stuff from about autumn 2004, so: problem solved. And when I next looked, in early 2010, everything seemed to be git+github, and all the better for it.)
Yeah you're too young. You need to be in your 40s (or older) to have been around in the open source community when Sourceforge was good.
(To quote a famous TV series... :-) Oh my sweet summer child
So you were ~10 years old. I'll assume not a heavy user of Open Source software, at that time.
Edit: 2001, I see one (1) banner ad, and that ad was seemingly for an OSDN (Open Source Developer Network) conference. https://web.archive.org/web/20010517002942/http://sourceforg...
Given SourceForge only hosted Open Source software, and had no source of revenue beyond ads and sponsors for quite a long time, AFAIR, I think they get a pass on a banner ad.