Gives three examples of bits of mathematics with really strong concrete uses.
Then says that category theory "does not itself solve hard problems in topology or algebra. It clears away tangled multitudes of individually trivial problems. It puts the hard problems in clear relief and makes their solution possible.".
Then says that category theory "does not itself solve hard problems in topology or algebra. It clears away tangled multitudes of individually trivial problems. It puts the hard problems in clear relief and makes their solution possible.".
And doesn't give any examples.
Still sounds useless to me.