Flax naturally has long fibres, the strands are several feet long, but, for modern spinning machinery's sake, they cut the fibres into short lengths. This makes it a bit of a pain to spin by hand
It's still doable, but flax is best spun dampish anyway, cut short like this I find it really does need dampened down.
If you want long length flax for spinning search for strick or roving. The strick is the full length fibres neatly laid out and bundled together, while the roving is the flax carded and drawn out into a continuous length.
In the past the short broken fibres were called tow, and were coarsely spun to make rough cloth. Ironic that the tow fibres are now the ones that are used to spin linen
maybe why so much modern linen is carp and wears out in no time. I have linens that are over 100 years old and they are still sound, beautifully soft and white. A lot of the modern stuff is dead in a couple of months of continuous wear by the reenactors
cheers,
Toddy