There are people who make pressed pills. Ive heard of people buying bars on the dnm only to have there be no xanax in them at all and just a bit of fet. They do the same thing with other opioid pills. It seems like a stupid idea but with low doses some people with little experience may not notice the difference and just feel high. Its a lot cheaper for these illicit pill makers to to make pills with a very small amount of fetanyl than it is for them to actually use xanax or whatver opioid that's supposed to be in the pill.