[Quekid5]

That's fair, but I do personally have a stance that compiler-checked documentation is the ideal documentation because it can never drift from the code. (EDIT: I should add: It should never be the ONLY documentation! Examples, etc. matter a lot!)

There's a place for type aliases, but IMO that place is shrinking in most languages that support them, e.g. Haskell. With DerivingVia, newtypes are extremely low-cost. Type aliases can be useful for abbreviation, but for adding 'semantics' for the reader/programmer... not so much. Again, IMO. I realize this is not objective truth or anything.

Of course, if you don't have newtypes or similarly low-cost abstractions, then the valuation shifts a lot.

EDIT: Another example: Scala supports type aliases, but it's very rare to see any usage outside of the 'abbreviation' use case where you have abstract types and just want to make a few of the type parameters concrete.