Also, AM voice on VHF is not full duplex and the blocking problem is very real and could be addressed potentially
I feel like, with proper UX in the cockpit and on the controller console, making it easy to send/acknowledge the clearance, and intrusively demanding immediate acknowledgment for important messages, with the controller able to talk to the pilot if it isn't immediately acknowledged, structured messages would save time, be more accurate, allow automated checks, i.e. be a superior substitute.
UX needs a ton of work and human factors validation, and would take 20 years to implement. But if you were starting from a blank slate it seems like the way to go!