Macbook air motherboard failure

Hi All,

I bought my macbook air in 2016 and it was covered under warranty for one year. It was bought in India and as soon as the warranty expired, my macbook stopped working all of a sudden. I took it to one of the authorised macbook repair stores. They suggested that the motherboard is gone and needs a replacement rather than a repair. Please suggest as why a repair isn't possible and how can an expensive and item like a macbook be so volatile and vulnerable ?