iPhone is labor intensive because Apple purposely makes it far more labor intensive than it needs to be. Most smartphone assembly is highly automated.low-end mfg is still very labour-intensive (think textiles, simple smartphone assembly). I think the automation challenge is really at the higher-end, that's where China is moving right now.
The new head of iPhone assembly said that while production lines for Chinese Android phones required only 100 workers each, the equivalent iPhone production lines needed 1,200 workers.
“For Chinese Android phones, we only have to assign 100 workers per production line, but we need 1,200 for the iPhone,” Chiang said, underlining Apple’s exacting demands.