Back in the early days, RC quality was very high, but it was only known about by a select few people, and it was exclusively psychedelics. Then it hit relatively mainstream and became extremely for-profit/a large industry, and stims/opioids/benzos/etc entered the scene. And quality really dropped. There are still very high quality products out there, and quality still is much higher than street drug quality overall (street drugs, in the US at least, are absolutely abysmal these days, all time low), but you have to be careful and have your products independently analyzed. Which I managed to do recently for much of my collection, due to participating in a research study that gave free drug testing. In the US we don't have any good, free testing services I am aware of, sadly. So miost people don't bother.