Yes its beyond the reach of most attackers to clone a chip card. Stolen card is still a problem though.
But the latter is not the problem that they even set out to solve. Fraud due to stolen cards is infinitesimal; most people don't lose their cards in a way they're easily found, and most people, when presented with a card, don't commit fraud with it. Not to say that it isn't annoying when you lose a card and someone does go on a spree, but it's always about the tradeoffs.
What chip-and-sig is designed to solve are the issues involving data breaches and duplicated cards. EMV means that retailers no longer have a vast database of all the information you need to produce a card, because part of the processing takes place on the card itself. Meanwhile good luck actually making a counterfeit EMV card, never mind getting the required information off of the original to duplicate it.