[vkou]

There's three broad ways to determine distribution of scarce goods. You've missed one.

In no particular order, those ways are:

1. Highest bidder.

2. Lottery.

3. Highest need.

There is no intrinsic 'fairness' to either of those three priorities to distribution - what any person thinks is the fairest method completely depends on their value system.

However, regardless of your value system, and your opinion on which of these is the most fair, you can probably agree that for luxury goods, #1 is a reasonably accurate proxy for #3... And that for life-necessary staples, it is not.

In the case of grocery delivery in the middle of a pandemic, people with pre-existing conditions, the elderly, and people living adjacent to those first two groups rank much higher on #3, than your run-of-the-mill 20-something-year-old. For the former, delivery is not a luxury good. For the latter, it is.

[renewiltord]

If they are truly life-necessary. But it is quite likely that the elderly and the pre-existing conditions folk will survive getting the bread tomorrow instead of in two hours.

We already have a bypass mechanisms for the "I'll die if I don't get it in two hours". It's the emergency services system and it's there when your life is in danger and it's currently overprovisioned to ensure capacity.

[vkou]

Which is why I was talking about grocery delivery as a whole, as opposed to two-hour grocery delivery.

The problem is if the express versus economy stratification does not actually increase overall system throughput - but instead, attracts more load to the system, as people who don't need it, but were otherwise going to the store end up using it for convenience.