I think you confuse what ports was supposed to do. It was supposed to be "make these patches NOW to make the software available to users" paired with "submit the patches upstream to ease future support burdens". But the latter didn't happen often enough at times, especially as people moved on from the FreeBSD project and complex software became unsupported. It's really no different than what all the distributions have to do on Linux, but had a different bias for forcing the question than FreeBSD did in the early days. That's largely changed, and has mostly worked out....

The bigger issue with 'large trees' is that there was no convenient, binary packaged way to subset. Having everything in one tree avoids much of the version chasing that you have with Linux packages that the package set maintainers have to grapple with...

Warner