no one knows how much .com is hurt by nGTLDs. Most end-users do not want nGTLDs even when it is available for reg-fee. Most who choose an alternative reg an .io or .ai or .co if they were stealing business from .com you would see this in registrations and sales which are low and decreasing. it is perhaps a few percent of startups who choose a nGTLDs. that alone would not hurt sales.