What discipline did you study in undergrad?
In many majors - or even just in well-taught classes - work outside of lecture or recitation is designed to complement what you are learning. It _is_ the education you're paying for. It isn't high school where it's a bunch of repetition of the same concept (although I'd vigorously defend that, too) intended as practice. Problem sets ought to be the application of the material you're introduced to in lecture, done so in a way that forces you to grapple with and connect core concepts to other material in your major.
For example, in grad school I TA'ed an upper-level undergraduate course that would typically have 15-20 students. The problem sets I created with the professor I worked for had problems split across two themes. The first was discover; we'd take something that seemed ho-hum or rote from class, and apply it to an oddball setting which yielded surprising results. Sure, that straightforward equation works - but why does it go so weird in this curated example we're providing? There's extraordinary opportunity for learning there.
The second theme was connection across disciplines. Introduce a mathematics, computer science, or other concept and use it to extend something from lecture in an interesting way. These problems were intended t be challenging. We referred students to other textbooks and invited them to work together or come to office hours to fill in gaps in their background, because (a) this is a _vital_ skill to learn, and (b) it led to really cool and interesting problems and solutions.
There simply is not time in lecture or recitation to cover the stuff we introduced in these homework assignments. That's why the course credit hours tallied up to 3x the amount of time spent in lecture. I'll also note that while challenging, we did not allow poor marks on or incomplete problem sets derail a student's grade. If in lecture/recitation participation and on exams they clearly knew the core content, we'd work with the students to ensure they got a high grade. But if someone shirked off the homework entirely but aced the exams? Well, the exams aren't testing everything we're teaching you in this course, so you better believe they'd get poor grades at the end of the term.
So your perspective seems warped. If you weren't doing the homework, then you didn't get the education you paid for, and that's on you - not the university.
