Was working on a client's stack and this one critical piece using ES (written by "experts" who had since left the company) was throwing an error every week at 2 AM triggering alerts and chaos.

After investigation I found nobody understood what it was doing or why. I thereby found the safest approach was to delete the ES implementation.

After that everything worked and everyone was happy.

I understand this thread is about dumping on ES... However, I must notice in your case it was an audit log. An ES system wouldn't work at all without access to events.

Yeah, the ES side of the system worked but was completely unnecessary. So loads of extra complexity, with no value for the business.

If the ES is "unnecessary", then it's not ES by definition. If events are not your source of truth, it's not event sourcing, just event logging.

I’m not sure what you mean. A car that sits in the driveway never being driven is still a car.

It's a cargo-cult car;)

Oh yeah, I've run into similar situations so many times. A critical piece of functionality was overnegineered and shipped, only months later did we find out that it never worked, and nobody found out because nobody used it.

this is absolutely terrifying

not if nobody uses it ¯\_(ツ)_/¯

It's similar to database backups - hopefully you'll never need it, but at some point you might. At that point you'd hope your data was intact

The cost of doing a database backup is usually much lower than the cost of doing event sourcing.