The fact that there are such libraries in existence means that there is no pain associated to this particular activity. Not only do you get great mocking frameworks, they are actually very robust and benefit from static types.
Mocking dynamically typed languages is monkey patching, something that the industry has been moving away from for more than a decade. And for good reasons.
> The fact that there are such libraries in existence means that there is no pain associated to this particular activity
I can say the same about Rails + RSpec. It exists therefore it's good.
> Mocking dynamically typed languages is monkey patching, something that the industry has been moving away
That's a reach. There are millions of javascript/python/php/ruby/elixir devs that don't use types or annotations. They mock. "The industry" isn't one cohesive thing.
Mocking dynamically typed languages is monkey patching, something that the industry has been moving away from for more than a decade. And for good reasons.