Theo Bekkers wrote:

We've had this discussion before and there's no argument that the
rolling resistance of a wide tire and a narrow tire are the same when
both are at the same pressure. However, the narrow tire will
invariably have a higher recommended tire pressure, so when a wide and
a narrow tire are inflated to their recommended pressures, the narrow
tire will have a smaller contact patch and a lower rolling resistance.

The argument that a wide and a narrow tire have the same rolling
resistance is therefore spurious.

It's by no means certain that:

1) a narrower tyre will invariably have a higher recommended
maximum pressure, or

2) a narrower tyre will be inflated to a higher pressure.

The argument in favour of wider tyres stands on its merits.

John