Thanks for reading! Yeah, my understanding is that these capture cards are fairly recent. I think my timing was pretty lucky because a lot of earlier projects had to do HDMI->S-Video and S-Video->USB[0] to keep costs down because there weren't any inexpensive HDMI->USB options at the time.
[0] https://github.com/Fmstrat/diy-ipmi#setting-up-the-hardware