What is the actual usefulness of TAF to an airline pilot
I understand if the forecast is for insufficient visibility or very high winds, or storms, but the rest of the time? Does it matter if there's drizzle or heavy rain? How much brain power do you spend working out the significance to your flight if there's a 40% probability that the weather will be rather worse for less than half the time period?
I imagine that besides TAF there's another source of information telling you the runway is expected to be under water or snow, or even that half a continent is expected to be snowbound.
For myself I look at TAF to get a better idea of how much rain to expect than I get from the public Met Office forecasts which are always for the worst likely case. I've spent too many fine days at home after the forecast has been for rain.