If I understood the “writing” issue clearly, its becuase in the old days, writing was a skill / craft (like tanning, ironwork, ect) and not something that was done by everyone and all the time. So like many other melochos that are not needed for immediate use, writing was put on the no list.
That said, I make every effort not to write with a pen on chol hamoed.
I don’t think computers even enter the equation. (unless you’re balancing your checkbook, just to get a head start on the end of the month).
Besides, CR chatting is not work, its a trip!