[kakadzhun]

Even if Reinforcement Learning is 'enough', it will be held back by whatever methods used to implement it (e.g. Deep Neural Networks). As the algorithms get more advanced, from some point onwards, to build the general AI, you first need a general AI to tell you the correct hyperparameters so that the pile of methods would work well in tandem.

Last but not least, you will be bound by your inability to accurately communicate exactly the behaviour you want out of the AI because you are incapable of writing down a mathematical function that would induce the behaviour in the learner. And then you wonder why the general AI decided to pull the plug on your grandma and try to use that resource for something else instead.