It's possible (and even likely imo if this is true) that Nintendo might be using technology like this
https://www.youtube.com/watch?v=JelhR2iPuw0 for digital buttons. This would solve pretty much every problem digital buttons have, since the screen is no longer actually flat. If they're doing this, they've probably partnered with a company that developed a technology like this. I feel like once you've got a production system in place, this type of technology might not (though I can't guarantee this without any info on exactly how it's manufactured) be that hard to produce once you know how to make it work. So it might not actually cost Nintendo much to mass produce a system with this type of cutting edge tech, and that it's cost might derive largely from licensing to use it