John Rumm wrote:

Do you take similar care walking over a floor in a modern house? Because
the same arrangement of floor boards exists there.

Chip floorboards are 22m or 38mm though, compared to 18mm for loftboards.

Remember you are talking about a 2' wide board adjacent and interlocked
with another, spanning one joist space - so there is no reason for it to
give at the edge.

I have certainly managed to crack the odd tongue off my loftboards