Swarm tractors
The reason why modern tractors are so big and heavy and expensive is largely due to the economics of having a driver in the bloody thing. Without having a driver in it you can reduce it to small possibly even wind/solar powered/assisted machines - you dont need to plough weeds under if you can send out a cheap machine that costs the good side of £1k and can wander up an down the rows autonomously zapping the weeds so they can never get going and need ploughing in later.
More importantly these tools can be mass produced to an open standard so, like my old grey fergie, I dont get screwed by JD for a JD special attachment that only fits my JD and cant be lent, borrowed or shared to people with people with different brand machines.