Discord is easy to set up, but the perms don't go nearly as in depth as TeamSpeak does. There are also the pokes and whispers in TS that Discord doesn't have. Those are the best ways to get people's attention. The biggest thing for me though that sets TS apart from Discord from a community standpoint is that TeamSpeak is that if I wanna find someone in TeamSpeak, I can search their name. Even if I couldn't, it's not that bad to just scroll down because of how compact it is. If we had Discord, if just our rooms from TeamSpeak were transferred to Discord, you'd be scrolling for a long time. Once you put 100-150 people in those rooms, you'll scroll forever to find the rooms or the person you want to talk to. Also, in this scenario, I'm ignoring the list of people connected on the right because that can be faked if someone set themselves to offline. Also, it's not a way to help you verbally communicate with them.
Honestly, the easiest way to transfer us from TeamSpeak to Discord without causing a massive Discord server would be to set up Discord servers for each division, which would just divide EGO rather than bring us all together. You lose the feeling of community that way.