I am a developer of software. I can guarantee you that what you’re asking for would make my job harder, because I’ve done it, and it has made my job harder. If an error is transient (like, a caching layer error, a db connection error, an external API error, an endpoint connectivity error, etc), giving the user an error code will make it more likely that they’ll file a useless bug report or support ticket. The errors are all logged internally, and we can see when there is a spike in the error count. There’s no reason to give the user an error code, because there’s nothing helpful that the user can do with it, and there’s a lot of unhelpful things a user can do with it.

There are times where a message to the user is appropriate, like if they made a mistake with their input. But there are so many things that could go wrong that the user can’t do anything about. You’re not going to work around your DB shard going down, and a replica will replace it in a few seconds anyway, so giving you an error code does more harm than good. Telling you to try again later is exactly what I would tell you if you filed a support ticket. I don’t want to deal with useless support tickets, and you don’t want to deal with useless error messages.

Modern software stacks are big, complex systems with lots of failure points. We monitor them, and we can tell when you see these errors. If we chose to not show you a specific error code/message, there’s almost definitely a good reason.