I explored this a bit and found there is a threshold of "too many tools" where people won't follow things on yet another thing that sends them notifications.
I think the magic number is 4: email, chat, wiki, tickets - we don't do much email so more like 3. The problem is none of those are good at longer technical discussions. With chat, threads beyond a day or so in the past are clunky to revive and follow. Wiki is better at finalized docs, tickets are short lived and any technical discussion should be settled by the time someone is working an item.
Really curious if others have found solutions.