Single chain rings are only useful if you need a limited range or more bb clearance. I have one on my commuter bike because the way to work is flat and I don't need more than three gears. I could use one on my mtb but 3x10 has a wider range and my skills are the limiting factor not my components.
You will save some weight but lose versatility. And you need to buy more expensive cassetttes.
If you don't cycle for a living you don't need the latest gear.