I wouldn't blame quality of materials for the dentures I have had in the past! Plastic is plastic, it is what is done with it that makes a difference.
First the impressions - whenever I have had these taken by a dentist (many times), they would overfill the mould, so that masses of the stuff squidged out at the edges. They would stand over me pressing the thing down, then test whether it was set too soon, so that the still-soft fill was squashed at the edges, blurring the shape. The experienced dental technician used only enough fill to make the mould, and was more accurate in when he removed it
When the dentures came back to be fitted, they always"had parts that rubbed, and often they wouldn't even go into place until they were sanded down. The technician's fitted first go.
After wearing them for a couple of days, I had sores and ulcers where they met flesh and aching teeth where the fit of plastic on tooth was too tight. Most of my dentists seemed bad at interpreting exactly where the sanding down needed to be applied - I found I was better using a bit of fine sandpaper myself on the spot that I knew was too high. My latest denture straight from a technician has not needed any trimming.
I may have been unlucky in my choice of dentist, but I can honestly say that only one of the dozen or so dentures fitted by dentists has been a good fit. ( I can't remember exactly how many I have had in fifty plus years ) That is why I bypassed them last time.