There is no real convention, no.

My rule of thumb is that if it makes the code cleaner and easier to read and maintain (this last point being the most important), then use streams. If not, then use normal loop iteration.

not for this task, way too slow

I disagree this being a best practice. It is clever and looks simple. Sure. But it is also not maintainable. As soon as point boundaries change, you have to rewrite the whole logic.

Looks clever, but this code is not easy to maintain. In case points change, and boundaries are no longer divisable by 10, this whole approach has to be rewritten instead of just updating the points.

Great!