Interface is really consistent, for example List and HashSet both have diff operation.
You could probably write a function that will supply you with the collection best fitting your requirements.
What I'm missing is combining multiple collections into one variable for sets of requirements that no single collection satisfies.
Also I'm not sure if Scala syntax could support other ways of accessing than simple indexing, like for example multi-dimensional indexing and slicing or even slicing by some inequality conditions like SQL does (with use of indexes into data). Basically if you could write LINQ and J in Scala syntax.
Even if not, the Scala collections look amazing and thank you for pointing me in the right direction!
After further inspection of Scala 3 capabilities, especially code quoting and splicing it seems that Scala 3 has all the building blocks necessary, base collections with consistent interface and syntax expressive enough to take it where I want it to be (Linq and J).