What is the point of Euro 6 technology?

Euro 5 technology introduced the use of add blue along with an SCR cat to reduce the production of NOx due to high combustion temperatures within the cylinder.The urea reacts with the catalyst to break the gas down into Nitrogen and water.But with Euro 6 spec exhaust gas recirculation is also tagged on which itself reduces combustion temperatures making the adblu cycle redundant as the NOx levels are already reduced before it even reaches the cat.OK the EGR only works on cruise and over run but the amount of weight,electrical loading and fuel consumption,never mind the cost of carting 50 litres of adblu about must outweigh any gain in lower emissions.Plus the cost to the environment of mining and refining the rare metals used to produce the cat itself.Is it to clean up exhaust gasses or just a way of making money via pointless and damaging EU regulation|||Sometimes we just have to trust that someone more knowledgeable than either you or I, has checked the actual figures out for all that and have found it beneficial to the environment.|||Yes in theory it works and helps the environment. In practice it will be an extra complication that will go wrong just in time to fail the MOT