I've played Splatoon 2 via LAN play. I had a group of people over two days in a row, and we enjoyed Salmon Run mode together. We set up our TVs in the same room, so we were all together playing. No need to yell across the house or even consider checking voice chat. Turns out I should have given it a try.
Apparently you can utilize a built-in voice chat feature via Splatoon 2's LAN play. All you need is a headset with a mic. Plug it in and you're good to go. Great for those who are spread throughout a single house for LAN play. Now if we could only get this feature for general online play!