Let’s be real — you cannot sing ‘Nessun Dorma’ that well without training.
RGR - I sang at the 8th Winter Olympics at Tahoe - we worked for months and were the only city in the US to be accepted with two choirs - Yea Oakland - OHS and Tech!
Yes, obviously he has had a lot of training. But the story is still about a guy who sells mobile phones who finally gets a shot. In their own way, performers on these shows have all had training. Some have had considerable training.
It takes hard work and complete dedication. That he would sacrifice so much to develop his gift makes his story all the more compelling.