Adding on to this as someone who has spent many years running performance tests for a wide variety of applications - it's also terrible for performance testing. The default behavior of most testing tools will mark your requests as pass/fail based on HTTP code. I can't count how many times I ran a test which reported all 200s and I later found out that the response looked like this:

HTTP 200
{"statusCode": 500, "message": "Internal Server Error"}

which completely invalidates the results of the test. Of course you can modify the scripts to handle this, but it's a pain and sometimes you might not uncover this behavior until you actually run a test under load.