Extending on that era’s TV programming (born in the late 70s), even if it wasn’t “your show”, there was only one screen in play. Secondary devices came much later.
It works quite well in practice, as KYC (know your customer) is in order for every state that has legalized it. Typically, a government-issued id#, SSN (last 4), and perhaps a license photo or selfie are required to open an account.
Whenever everyone can come out and play, I highly recommend a visit to Bletchley Park (conveniently located in Bletchley: https://bletchleypark.org.uk/), and, adjacent to it, The National Museum of Computing (https://www.tnmoc.org/).