I agree with 2 of your points, but the third makes me wonder whether you work in the same industry that I do.
But sure, if you had a terminal, a spare IBM system (the iSeries is probably the lowest end) set up to support SNA, and then a networking controller to attach the 3270 to, you could probably get Lynx working.
Alternately, if you just want the effect, you could just pick up an old green/black monochrome display and hook it up (via a physical adapter) to any VGA card. Buggy implementations excepted, all VGA cards should be backwards-compatible to MGA.
Add a nice IBM Model M keyboard and you'd be all set. I suspect someone has probably done this as a case mod before (if not ... I might); stick a modern mobo in an old IBM PC case with the original monitor and keyboard.
Terminal-based systems often have a very steep learning curve, but I've seen many cases where they were better designed and met business needs better than COTS replacements.
Granted, those terminal-based systems were probably phenomenally expensive when they were put in (mostly in the 70s or early 80s, that I saw), and I suppose it's possible that after 15-20 years we have a biased sample that only represents the best of the breed, but they got the job done.
I judge how good things are by the human element. That hasn't changed. The software industry is as inclined as always to engage in death marches, shortchange quality, seek imaginary silver bullets, and devalue experience. In short it isn't fundamentally different at all.