Which of those TQ’s is easier to apply to one’s self. As as example, in the video the guy applies the TQ to his left arm using only one hand.

In the Wilderness First Aid course we learned to fabricate a tourniquet from available items. IIRC I used a triangle bandage and don’t recall what was used as a windlass, but that too can be fabricated; it’s not rocket science. However, the TQ’s were being applied to another student in the class and not to ourselves. The ability to apply one to your own arm using only one hand, is a good reason to carry and practice with a purpose built item.