Personally, I am either playing with friends using Discord, or if I am lone wolf and playing without friends, I just go for it as best I can without comms. I found you can want to use mic in proximity or squad, but if you are with people who do not speak your language, you are a bit stuffed! I think your suggestion of proximity or squad in-game comms is good but may not come to much. I remember the Halo 3 days, it was great! but you soon had a lot of foul language and then people playing music and being generally rude and annoying.
Private chat is the way forward, public chat can't be policed. Unless I am missing something... Thoughts anybody?