I think this post has some interesting points, but it kinda misses a few more as well.

First, appropriate tone depends heavily on the product or service in question. A bank or otherwise serious business should probably not be giving messages like "whoops, something went wrong". But an entertainment product could have those sorts of messages, and treat it as part of the overall experience.

Secondly, I'm not a huge fan of error messages that don't give actionable feedback for how to fix the issue. Yes, a lot of users don't need that sort of information, but some sort of error code or technical reference can be handy for more involved support processes.

So, if the product or service is business orientated, maybe have that info in a dropdown box or something, where a support agent can ask the user to find it if an issue keeps occurring. And of course, if the product or service is aimed at technical people (like an open source infrastructure project), maybe just skip the casual language and just get to the point.