I know nothing about grocery retail but my initial reaction is why can't Instacart tie into Safeway, Wholefoods, etc. inventory management system to get a more

I know nothing about grocery retail but my initial reaction is why can't Instacart tie into Safeway, Wholefoods, etc. inventory management system to get a more timely view on what's available? Are existing grocery inventory management systems more rudimentary so this is not possible?