Earlier quoted context omitted.
This shouldn’t surprise you. Most people can infer gender from visual appearance alone with well over 99.99% accuracy without being explicitly told. If you know their name and other gendered indicators, it would be a marked anomaly NOT to know their gender.
I can also infer race from visual appearance with similar accuracy, but if I say "Can you hand this to that black person" would be super weird and quite likely objectionable, even if I was correct that the person was black. And nobody would want abbreviated pronouns on race - "I talked to whim and whe said to talk to blim" just seems sort of ... overly concerned with people's races. It's a linguistic quirk of English…
Whereas always marking what continent you're all living on, or what race you all are, usually doesn't convey any information. So it seems entirely unsurprising that languages tend not to build this in. Many do build in markers for what species, because again this was useful information, since most of our ancestors spent a long time farming.