we don't know how the brain functions, and that's a big problem. we're trying to replicate an idea that we don't know how it works. io input could be the right path if you understand the wave frequencies and align them to actions like Elon is doing at neural, but even that is an extremely slow and a very inaccurate process. that guy hypes everything, and the tech looks like a promising start, but we're so far off from understanding how and why electrons travel like they do to the synapse. or how synapses communicate.

yes gas is also a problem, but nobody can make battery density better and currently it's like a 40:1 ratio, meaning 1kg of gas is 40pc more efficient than 1kg of battery density. that's a huge disparity, that the average person doesn't realize. and actually is one of the major limits to space activity. solve batteries and we'll have space travel, ion propulsion is great, feasible and ready for testing.

solve batteries and we'll see new things invented. please work on some of this if you can.