@ephemeral The tl;dr; is that I reason that a web browser could be implemented largely using hardware designed for parsing & serializing data, basically variations upon memory circuits.
What little arithmetic processing that leaves would more than fit in a 6502-era computer. I explored a design which had more memory (and a barrel shifter), but is otherwise very comparable!
Then there's the question of GPUs... What we have now is more than a browser needs, what we had then is less than desired.