I have also reported this previously and it is for sure annoying. I find that many of these types of setting tell us how we want things. I understand the purpose of defaults, but people need to understand that as years move on, those old standards are not so concrete anymore.
To place some real reasoning here, I live in the US. My date/time formatting is “2019-12-26 21:30:39”. The problem this resolves for me is mass confusion on formats. For example, the confusion between 12/10/19 and 10/12/19… is it Dec 10 or Oct 12? When a time says 7:10, is that AM or PM as sometimes that is not in the time stamp? I like to configure my locale to a format that is easy to read and clear, non ambiguous. I understand it is not really a functional issue, but it is an annoyance having to always think first when looking at a time/date stamp to make sure you read it correctly vs having consistency to my actual preference. IT is also worth noting that although the US still uses the AM/PM stuff, there are plenty of business here that use 24 hour time, especially in logs, reports, etc.