I did factory work for a year and it was tedious and I was glad to find another job.
Doing any job for too long can get boring but people continue to work at the job because they need the money to pay rent, buy food and keep their kids warm and fed and clothed.
I don't think I would've lasted much longer in that factory job myself and probably would've just offed myself if I had to work their doing the same ole thing over and over day in and day out for the next 30 years.