The basic Laker Skytrain proposition was no forward booking (though that was modified), meals were bought in advance when buying the ticket, drinks were charged on board, dutyfree was sold agressively, legroom was just about acceptable (I'm over 6 foot), he cancelled and amalgamated flights at least as often as airlines do today, and charged £59 one-way to New York.
The majors squashed him when he ordered large numbers of Airbuses and applied for 600 routes around Europe. Regency Class was never a wild success. The final straw was the dramatic change to the dollar exchange rate which destroyed his cashflow.
I do not see a problem for an airline to operate a modern version of Skytrain using internet booking systems. The problem is to keep a charismatic boss from believing his own publicity and wanting to do more and greater things rather than sticking to a proven (and ultimately boring) formula.