All the web developers I've worked with in the last four years understand the concept of a bottom type, even if they've never been introduced to the formal phrase, because `never` is the explicit bottom type in TS and appears all the time. You can't go very long consuming libraries written in TS before you run into it, at which point you become familiar with it.

Similarly, a function that accepts (explicitly) `A | B | (C & D)` and then dispatches to functions that accept `A | (C&D)` vs `B` is, you guessed it, type algebra and is a common pattern in hot paths through every TS codebase.

Just because the formal nomenclature is unknown does not mean the concepts are unfamiliar.