Listen as cypher groans about life in the resistance. Constant fear and anxiety from the bots, shitty food bricks etc. We all like to pretend we are tough as nails and can take any hardships, that attitude changes quickly, especially when you can see and even manipulate the alternative life in the matrix.
I think there was a point where cypher wanted to fight and be a genuine part of the resistance, the stress eventually got to him. How many "chosen ones" before neo did he see come and die? Eventually it seems hopeless and he could probably game the matrix just right to have a good, albeit artifical, life for himself. It would be like having an option to go back in time and buy amazon/apple/nividia stocks at just the right moment.
Resistance is often painted as easier than it is. It sugar coats the losses. It makes losing 25 people to kill 5 agressors a "victory". The actors stay fit and strong even if their characters are getting 1 meal a day.