Even for short distances, a better device is more pleasant to use. Not sweating is worth a lot if you can't shower at your destination.
And what if you want to travel 10 miles? Or 50? Carry more cargo, climb steeper hills? I think you should adopt this moderate position from a competing industry: "your mileage may vary."
A cardboard bike is probably not great. Bt getting people on bikes is important. If they have an okay experience on a lousy $10 cardboard bike then there's a chance that they go on a buy a bike and use it.
And, like everything else, there's a lot of nonsense spoken about bikes.
Most people do not need carbon fibre frames and titanium widgets etc.
That's assuming it's still there when you want to use it. A well maintained cheap bike might take 5% more effort to use, but being able to use it in more places IMO is worth more than being slightly less tired when you get there.
And what if you want to travel 10 miles? Or 50? Carry more cargo, climb steeper hills? I think you should adopt this moderate position from a competing industry: "your mileage may vary."