You picked two languages (Java and Python) with extremely weak guarantees about disposal of resources when exceptions are thrown. Any time I acquire a non-trivial resource I must make sure it's disposed of properly, via a `close` etc. method. (And these are most cases of interest; acquiring trivial resources e.g. memory shouldn't need error handling in Go either.)
This isn't theoretical. I review a lot of Python code and I would say in over 20% of cases I see a try block with a `finally` longer than two lines, it mistakenly uses a variable that might not be set when an exception is thrown earlier than the writer expected.
When a controller calls a couple of gateways and a database access layer, it is almost never holding resources. I would agree that testing error handling is more interesting when there are resources to clean up or fallback logic to implement. That's just very rarely the case. Mostly I just need to bail out of the request.
This isn't theoretical. I review a lot of Python code and I would say in over 20% of cases I see a try block with a `finally` longer than two lines, it mistakenly uses a variable that might not be set when an exception is thrown earlier than the writer expected.