For example, in Scala's standard library there are a ton of implicit conversions that results in some truly horrendous behavior where types get autoconverted hi

For example, in Scala's standard library there are a ton of implicit conversions that results in some truly horrendous behavior where types get autoconverted hither and thither if they don't match. So instead of a simple type error, you get nonsense when the compiler manages to find a way to cast A to B. And then you might get a crash because you used B wrong. I have heard that this is one of the things that Scala 3 fixes, but I haven't done any programming in that yet.