Reasons why Optimus might be easier than FSD, at least for performing boring, repetitive jobs in a factory.
Safety
FSD controls a multi-ton machine zooming around outdoors at lethal velocity, with risk of catastrophic damage to life, limb and property if the wrong decisions are made even once. Teslabot is a ~125 lb machine with a maximum speed of 5 mph operating in a controlled indoor environment that, at least for initial applications, could have humans excluded from the vicinity. Teslabot simply requires drastically lower levels of reliability to be considered functional and be allowed to operate without human supervision.
FSD also has to work within tight constraints on processing speed for the inference engine, because at highway speeds it will travel a meter in 30 milliseconds. Traveling too far while waiting to make a decision is unacceptably risky. Teslabot doing a repetitive factory task can afford to take more clock cycles to perform more computations to reach a higher level of certainty about a classification decision before acting upon that information. If I understand correctly how the FSD computer works, this means Teslabot could use deeper or wider neural nets if needed to improve inference performance.
Simplicity
FSD has to deal with a huge variety of potential environmental conditions and problems to solve. The lighting varies, the weather varies, and there is a factorial explosion of possible combinations of lane lines, road designs, pavement materials, other road users and their behaviors, etc. FSD needs to be able to solve almost every imaginable setup to reach the required level of reliability. Nothing has more degrees of freedom than reality.
Teslabot will initially be restricted to boring, repetitive tasks, operating in a controlled factory environment with almost perfectly constant lighting conditions, sheltered from all weather. It also will generally only need to know how to do one thing, and by virtue of only doing one thing, it will also have less challenge with overfitting to the training data, because the training data will be almost perfectly representative of the data it will see during test time (i.e. doing the job).
Sensors
FSD has to compensate for factors that distort camera readings, such as vibration and rain/dust/other debris occluding the housing over the lens. A factory Teslabot would have minimal vibration and no sources of occlusion.
