Obviously to an extent it can be compared, but considering laws aren't the only difference (economics of how many people in each country need work at what price, culture of who owns cars vs uses taxis vs cycles, etc etc) it would take an awful lot of analysis to compare them usefully (which no doubt various people both inside and outside Uber are doing, of course - and Ive no knowledge of how successful they are at that).

You couldn't just look at one being twice as profitable and say "that's the effect of country A's legal regulations vs. country B's".