People have no conception of how enormously heavy even a section of tree is. Have you tried rolling a one foot section of two foot thick tree trunk on the ground? You quickly understand what you're dealing with then.
I once witnessed a six wheeler tow truck designed for towing buses and coaches and other trucks being used to pull a root ball out of the ground with chains. The tyres sqealed and smoked but it finally managed. The root ball was about four foot in diameter.

Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!