The controversial eraser tool

[pauland]

It's "another" in this case.
Vector eraser IS a vector tool. But with some drawbacks.
Imagine you have drawn lots of quick strokes. They are all lines. Now you trim them a little bit with eraser. Let's say half of them were affected by eraser. They were converted to shapes. But the rest are still lines. You can still change line width, pattern, profile, even apply brush to them. But not to those that were affected by the eraser. Surely, they are all vector, but the result is not quite consistent or predictable.

A line cut by the eraser becomes two lines. Shape cut by the eraser becomes two shapes. A long line erased at the end becomes a shorter line. It's entirely predictable.

Doesn't really matter if you cut a shape or a line.