The article from the New England Journal does not say there is no risk. It says the risk is very low. It does not say it's impossible, it just says that it's highly unlikely.
The reality is that even though the risk of getting infected from from food and store deliveries is low, it's not zero. There's still a chance it could happen. I personally don't want to tell someone "go ahead you'll be fine" and then find out they were the long shot that did get infected from it.
Even with my parents, one is mid 76 the other one is 81, I've just been making sure they understand all the different risks and then letting them decide what risks they want to take or not.
Safer does not mean completely safe. Not much risk does not mean no risk at all. Those are important distinctions to understand right now.