This mirrors my experience. When I was in college I was always able to plug some random person's printer in via USB and it "just worked". I'm also able to autodiscover and print to all of the laser printers at work. (this is on Linux)
Have you tried debugging things when cups doesn't "just work"? printcap was much simpler, which made it easier to understand and diagnose problems.
In general I think there's a positive correlation between the precentage of cases where software "just works" with no manual intervention and the effort required to diagnose the cases where it doesn't.
Yes, I spent plenty of time debugging CUPS in the old days. But I haven't, in ages. printcap may have been simpler, but shortly before CUPS was released, the linux implementation had matured significantly and could do many basic conversion operations. Distros supported this and handled things like ghostscript conversion.
These days, I print in a number of ways that work fine, including Mac OS X (a version of CUPS which has already been debugged and polished for many printers I use), Windows (my preferred printing system since it supports the largest number of printers), and Google Cloud Print (for the set of printers I use that have that as their access protocol).
