There's a difference between providing everything and providing some simple features. A drummer could hit a cymbal and then use a hand to stop it. A drum sampler could provide triggering a layered cymbal sample and silence. If the sample and the silence are in one group, the silence will stop the cymbal. This does not sound equal, but similar to a drummer stopping the cymbal, played by a MIDI keyboard or by drum pads.Even if a drummer should play a drum sampler by drum pads or mic'ed drums, the drummer is able to use different technics when playing a drum sampler, as well as when playing real drums. Yes, even when plying very expensive drum pads and special drum pad cymbals, this doesn't provide everything needed to fake a real drum kit, but OTOH it provides things a real drum kit can't provide. IOW the target of a good drum sample not necessity is to fake the things you could do, when playing a real drum kit, but even if you use samples of good old drums build in the 70s and earlier (for good reasons drummers tend to buy old second hand drums, instead of those build today), you don't need to use them to fake the style of John Bonham, let alone jazz drummers. MIDI has got limits, but also enhancements for the creative musician. We should expect that everything that is called a drum sampler, provides some basic features that are useful to produce rhythm, without having in mind to fake real drums. I sometime sample my guitars. I'm a guitarist, but plying the samples by a keyboard allows me to use technics That don't exist when plying a al guitar. Yes, I can play a real guitar with toilet brushes, hey, We also could play a keyboard with toilet brushes. This sounds different, but still would have impact to the result. If you play the guitar with toilet brushes it does affect the sound a lot, if you play samples by a keyboard with toilet brushes, it does affect the playing style a lot.