Some jobs are bad. Some people are bad at their jobs. Sometimes it's both at the same time.

This furniture assembly job sounds like shit. But also, somebody who puts in "several hours" of labor should be able to assemble some off-brand Ikea slop by simply following the instructions and using a little bit of common sense. If the pay is terrible so you don't even want to try, I get it, but you should bail quick not after "several hours", so it sounds like an earnest (albeit incompetent) attempt was made.

This job sucks, not because there isn't training, but because the pay is too low to attract competent labor.

Karl Pilkington, how art thy welcomed.