because card reader support is still shit in browsers in 2026

Around a decade ago I was working at a company that used smartcard login for authenticating to internal sites. I've heard of many others doing the same. USB card reader worked fine in both IE and Firefox at the time, so I take your statement to mean that we've somehow regressed since then (not surprising) or this was an isolated instance of success (less likely, considering the US government also uses this: https://en.wikipedia.org/wiki/Common_Access_Card).