I don't disagree with you from a performance standpoint with the laptop, but for me, it was highly inconvenient leaving my laptop at the music console all the time physically connected by USB to the DAC. Furthermore the UPnP implementation on the Marantz M1, I found, is not completely stable/reliable, so using Audirvana to play to it over WiFi wasn't a great experience either.
From an experience standpoint, with a good UI like WiiM or Eversolo devices, you get to focus on the music and not on the act of playing it, if you get what I mean. And it just works. Sure, sooner or later, there will likely be an end-of-life scenario from a software standpoint a few years down the road, but for me personally, I can live with that compromise given the benefits. Plus, it may stop receiving updates, but it's not like it's going to just suddenly up and cease functioning all together.
-Ed