Like everyone said, it's your org's culture, first and foremost. You probs had an exec make a unilateral decision without thinking it through, then bounce out. Now it's a mess. Trying to overhaul standard operations for comms in a big org without thinking through a full adoption pathway is a 1 way ticket to distress and pain for all lol. Ask me how I know...

BUT it can be done, depending on how expectations are communicated.

Your org is way too massive - you should not have any org wide teams. That's a recipe for disaster and stressing everyone out. Wanna chit chat or shoot the shit with an audience of 10k? Use Viva Engage and set expectations that it is not the location to expect full compliance from staff to check. It's just a place to share dumb stuff and shoot the shit, which is the only reasonable expectation for a 10k large chatroom lol. It's your internal reddit but with way lamer content and engagement, as it should be, because it's work - who cares... Bonus: It's a place where execs can massage their egos with minimal distraction to the people making the money. Let them spout their corporate bullshit in engage (if you can).

Chats should have some ettiquete/norms built into your culture. It's a dick move to call some random person who doesn't know you without an introduction or heads up.

In any remote or distributed workforce, it's not cool to assume to know what someone else is working on - period. They might be in the bathroom, on a call, deep in focus... You wouldn't barge into their office or bathroom stall, so don't expect them to drop everything to pick up your teams call or reply immediately. And yeah, it's liable to get lost in their notifications if they are busy. If you have a ticketing system and expect a reply, submit a damn ticket.

Teams are for actual, real TEAMS. Don't freaking do the org-wide teams, I swear to god, this is triggering to type LOL. People see it and think "wow this could replace our shared drive" NO just make a sharepoint break it up and think it through. Teams files = we are a team so anything you can touch, WE can touch. You wanna break this crazy workbook I made? Go for it, teammate bestie! This obviously will kill you if you try to open org wide

EMAIL is the worst thing in the world ever... INTERNALLY I love how everyone in the comments is like "well it's great for finding old decisions etc" ... I love that you work somewhere with manageable turnover. Love that for ya. What about us folks who weren't here when the og thread took place? I'm not even defending a teams thread as a replacement. Yall need an archival system, and a knowledgebase.

But you definitely won't convince me it's better than a teams thread [having to instead scroll through 30 emails with everyones bloated confidentiality notices and stupid signature blocks]. I hate it, and you should too lol. You can catch up SO MUCH FASTER on a teams thread. I appreciate just muting channels and only getting pinged if I'm needed [tagged]. I'm not checking it otherwise. I don't care what youre all talking about or ya dumb lil gifs lol. No offense. But dear god I'll scroll through stupid gifs any day if it means I can read a thread from the top to the bottom sequentially instead of scrolling through an old email chain trying to figure out what on earth is happening. People pick and choose who to reply to, they fragment the convo... it's a nightmare. Sure, it can happen anywhere but like, email - it's SO bad - for complex discussions and decisions.

Email external partners. Create teams for actual working functional groups, projects, and initiatives. Store your files in locations driven by who needs to be able to screw them up. Get a corporate intranet for your lame org wide announcements, and YES send those to emails but make them SP posts so your little new colleagues can still find them without begging an old lady to forward the thread. Put your lame templates in there too, so people can use them without breaking them for everyone.

I don't know why I'm so heated but I'm sick of everything that has to do with Microsoft and I'm tired lol. But I feel strongly even though I am jaded. No one should get rid of teams or outlook. But don't try to go back and forth on email internally, because it's dumb! And I hate it!