They probably know what it is but are just not familiar with the term.

I find the OS' captive portal detection to sometimes be flaky, so I often just directly visit www.neverssl.com to reliably trigger the captive portal redirect.

I just like reading random Wikipedia articles. You could farm HN karma off me by posting random ones each day.

I bet RFC 8910 is not well known.

https://www.rfc-editor.org/rfc/rfc8910

I think it was 5+ years after first having an ipod touch (i.e. connecting to wifi while out and about) before I encountered the term, and never heard it widely used outside of text on the internet. Doesn't feel like it was commonly used, a la, "Complete your connection to our wifi via the Captive Portal after doing XYZ!"

Was wondering the same, most (even non-tech) people come across captive portals all the time.