Nintendo's phone app for the Switch was updated today, fixing two really annoying issues with voice chat.
When the Nintendo's Switch app launched, people were happy to finally be able to play Splatoon with voice chat, but were disappointed that voice chat would disconnect if you tabbed to another app or if your phone went to sleep. Both of these issues have been fixed with today's 1.1.0 update. I gave it a shot and it's still annoying in a lot of little ways, but voice chat worked perfectly when I browsed Facebook on my phone and put it to sleep.
You still have to use the cumbersome headphone splitter if you want to use voice chat and also hear the game audio through your headphones, but this update gives you a little more incentive to use it for voice chat rather than just calling up everyone on Discord.