Your example has absolutely nothing to do with UBI, other than the fact that a small minority gets paid a stipend. It's not universal as it's conditionally granted only to a very small subset of society (students) throughout a limited time (5 years). At best it's another social safety net that is granted to people who would otherwise have no access to higher education.
Yet, in your example you already acknowledge that even when granted to a very specific subset of society which is motivated and mobilized to seize that opportunity to fund personal growth, it is also abused in ways that go exactly against it's purpose as it provides perverse incentives that attack equity at it's core.
> I don't personally believe that the majority of people will become unproductive consumers with an UBI. I think that societal pressure to contribute, the wish to enjoy luxuries, and to get status is enough for the majority to still work.
I'm afraid your personal hopes are misguided and based only on wishful thinking. There are plenty of examples in areas such as social housing where benefits are linked with immunity to "societal pressure to contribute". Providing a resource unconditionally represents a clear incentive to eliminate whatever incentives there are to secure it.