> Whereas Roman script can represent the accurate pronunciation of every word in Hindi

Isn't this only true if you already know how Hindi specifically is supposed to be pronounced? I don't think you could show someone a romanized Hindi text and expect them to even come close to an accurate pronunciation. For example, doesn't Hindi have like six ways of making the English "D" sound?

Same thing for e.g. Chinese, you can't represent tones with unaugmented Roman characters.