My point is more that the compiler* can't detect these mistakes but in other languages you can. E.g. in Haskell you only allow Null on types when you want it (you do this by using the Maybe type). Objects where you probe for values that could be undefined or could be defined but null doesn't exist as a concept but if you badly wanted it you could use a dictionary. In Haskell if you use Maybe and you process a Maybe object you have to deal with the null and not null case otherwise you get a compiler error.

All these checks seem annoying but we've all seen the bar chart of when you discover the bug vs. the cost of that bug. The compiler finding the bug is cheap. Haskell is a cheap language to program in, compared to JS!

* I forgot there is no compiler in JS but let's say the linter for argument sake.