Several algorithms have certain parts with a concrete type.
The algorithm might operate on a concrete data structure or have a part of the algorithm where the variable has the same concrete type no matter what type of input comes in. For these, adding convenience like showing attributes autocomplete option when you type “x.” and so on can be nice.
There might be more we could do (for example inferring AbstractFloat to only output AbstractFloat), but that’s beyond the scope and is probably harder because Julia was not designed to infer abstract types, only concrete ones.