I think it depends how tightly your business logic and your view are bound and how well your business logic is abstracted. I use Angular at work and 90% of the bugs we get can be caught by a unit test. On a rare occasion something will be mis-labeled on the markup and the two-way-binding "fails" silently, but usually our bugs are errors in the logic.

Whenever you fix a bug in your code, try to cover it with a unit test. If you can't, ask yourself whether it might be because the code is poorly abstracted.

I think there are definitely varying degrees of value in unit tests. Your example is definitely not super valuable, but unit tests on higher level methods can save a lot of trouble. When I code I want to rest assured that the different pieces I am using work. I want assurance that this class I'm about to use has an API that does exactly what it says. If I want to change modify the class, I want to see exactly what assumptions I'm breaking that users of this class might be making, and I want to be able to do this in under a second. This can have a drastic impact on developer velocity. I don't know of any other way of doing this than unit tests.