A single separator is better than a choice of separators to mean the same thing.
A space is not as apparent in a large log of data as a capital T
Human language is not as strict as a programming language. There is a reason you see people still using “alot” and “a lot”. That just proves it’s easy to overlook and commonly happens.
The difference:
2023-12-12T21:18Z is ISO 8601 format
2023-12-12 21:18 is RFC 3339 Format
A small change
I definitely don’t agree that the RFC is easier to read, the two numbers can appear to be one at a quick glance without a separator.
But there is a separator between the numbers: the same one that also very reliably separates the words in this comment
Both are valid (if you’d add seconds) in both RFC 3339 and ISO 8601, but timezone support is the same here and there…