People will complain about anything, though.
The nature of my work has me dealing with all of these platforms, depending on the clients. Guess what? I don't find Slack to be some joyous piece of software to use. It's better than the alternatives, I guess, but not to the point that I really care one way or the other. Some people complain about the bundling, but that can be really convenient for your organization.
If you have <50 employees and you are standing on principle against the completely bundled cable TV vertical that Microsoft is offering, I genuinely question how much you care about the success of your business. We should be able to have a rational, business-oriented review of their value proposition - as of 2023, not 2010 or 2018.
Organizations that have a lot of loose capital and cowboy investors might be more interested in playing in traffic with 20+ vendors and horrible integration stories, but we (aka our <20 employee org) really need to ship solutions to paying customers or we don't have any jobs in 12 months.
I always hear everyone complain about how expensive it is, but I feel like John Travolta meme each time I look at our Azure/Microsoft account. The per-seat & consumption/serverless billing models feel like dust in the wind when you have so few employees. Everyone is doing a lot, so why not put a lot of power under each seat? If you intend to do more with less people, I really feel like Microsoft is the answer. If you are a F100 org, I totally get it. Fuck Microsoft. Use something totally different. Build your own datacenters.
If you run a <50 person company, and you're bike-shedding about which chat program to use, I seriously question how much you care about your business.
Yeah just like the AD bundling with windows was convenient. Up until you had no other choice than retaining an AD if anyone wanted windows anything.
But when it's your main communication method, you want people to enjoy it, use it, and want to use it more. You don't want people to avoid communication because they have to use a crappy IM client. These small differences have huge impacts.
I've used all of them in the past, and Teams was, and still is, the one I avoid chatting with someone unless absolutely necessary.