What key production stage presented the major bottleneck in mid-18th century English textile production before the Jenny?

Answer

Spinning yarn

Innovations like the flying shuttle sped up weaving, leaving the manual task of spinning yarn as the primary bottleneck, as traditional wheels produced only one thread at a time.

What key production stage presented the major bottleneck in mid-18th century English textile production before the Jenny?
inventionevolutionmachinetextilespinning jenny