I've been commuting to school or work by public transport since I was 16 and in 4 different European cities. Getting any seat is uncommon, let alone one where pulling out a laptop and getting work done was even an option. The only public transport option where I can conceivably see getting work done are the intercity trains, and then only if you get on at one of the very early stops before the train fills up.
Personally, 'can I get to the office by foot or bike' is one of the most important questions I ask myself when looking for a new job (or house). Commuting by car and public transport are both suboptimal.
Most people, throughout history have had a fixed time budget to get to work. They move if the trip takes more than half an hour. They will not take jobs (or will move) if it is farther away. We see this across civilizations, from hunter gathers following herds to modern people. There are exceptions but they are exceptions.