Aside from the obvious benefit to having a Web that's less broken for everybody, one of my previous projects at Google was implementing support for multiple scripts in a mapping product. I literally don't know how I could have pulled this off without Noto: all other alternatives would have involved some combination of subpar quality, incomplete coverage, incompatible appearance or near-impossible license requirements.

(Standard disclaimer: I work at Google, but these views are my own, not Google's.)