Your budget might also be the cause of production shortcuts. You may ask for premium quality everything in your tech pack, but if you don’t have the budget to match, you will have to compromise somewhere.
If your sample or production from the factory is lower quality than you expected, it may just be that they are giving you the best product they can within the budget you provided. Factories don’t have high profit margins, so if you ask them if they can make it cheaper, those savings will have to come from reducing the cost (and quality) of the materials or reducing the complexity of the sewing.
I do think that a good factory should bring any quality-budget misalignment to your attention far before a production run is made, though. This should be a conversation that happens early on – right when they receive the tech pack or after they’ve made one costing sample.
Like with many things in life, you get what you pay for with garment production.