This is ultimately the bottom line. So when considering 2x12 vs 1x13 it essentially comes down to whether or not you can ride with 2 less gears vs your tolerance to repeated front shifts if your riding terrain demands it. 2x works well if you are riding mostly on flat or consistent gradients with the odd isolated steep climb. But 1x works better on constantly changing terrain that would require loads of front shifting with a 2x. My local roads are very much the latter, which is why I'm pro 1x13 as a viable alternative to a compact 2x.