Thing is, even with the pressed pills they would contain such small amounts of fent as the sellers don't want ro kill people. They want return custom. Its just that it's so easy to get it wrong due to it's potency so there are batches of pills that will have a sudden spurt of overdoses attributed to them. The news and media report it like its a constant thing.
As far as strong opioids go, there are quite a few potent analogues. Some more available than others. Some far stronger than fent. Butonitazene, etodesnitazene, flunitazene, metodesnitazene, metonitazene, N -pyrrolidino etonitazene, and protonitazene for example. Not all are are steonger than fent but a good few are. They were quite easy to get up until a fairly recently. I actually found a few of them in abundance on a Chinese manufacturing ebay style site. Basically all the Chinese labs would have account there selling their chems off. Unfortunately it looks like there's been a recent clean up/ban on such substances as my searches stopped bring up results there. They do still have it on there but it's not as prolific as before. They seem to be getting around it by using slightly incorrect spelling at the moment or advertising generally but leaving out the specifics in the main listing until you click through and then see it all listed. I can't say how reliable they are as I've never used them myself. I am inclined to think they're 'legitimate' sellers but these substances have been scheduled in the US now so importing them is not without its risks. I've been tempted to request somw samples as they do offer them but the risks involved with shipping put me off. I can't say I'm not still tempted though. Incidentally I browsed some darknet markets and found it there too. Again sent from China.
But yeah, basically these things exist and are obtainable it seems. We just don't know enough about them to consider them as good/reliably peaceful ways to ctb.