That wasn't the reason to restrict block size. There is no way to scale the number of transactions on the main layer to anywhere near the level required to cover daily transactions. The bitcoin main layer was always destined to be for settlements between financial institutions anyway. Making any accommodations for use cases that are fundamentally unsustainable never made sense. Buying coffee was always going to have to be on a second or third layer, so restricting the block size introduces an incentive to develop those layers that are needed anyway.