The point of type checking isn't so much to prevent bugs in production, but to speed up your development loop by catching many errors before you've even saved y

The point of type checking isn't so much to prevent bugs in production, but to speed up your development loop by catching many errors before you've even saved your file. Its much faster to see a red squiggly right after you've written a line of code, and fix it, rather than figure out whats gone wrong 10 minutes later looking at a stack trace in your test suite.