Block mode terminals are somewhat similar to the forms based UIs we later got like HTML.

The 3290 was like a 4 split tmux session, it is such a beautiful device (https://ifdesign.com/en/winner-ranking/project/ibm-3290-info...). Perfect keyboard, plasma contrast and the right text color for long sessions. My understanding is they outlived themselves with long service in air traffic control (supplementing vector/raster displays), financial markets, and software development. Once upon a time people seemed to really care about doing things well.