Yes, it's a "basic" chat app. Like google is a "basic" search engine, how hard can it be to make something like that? Just make it go search?
Teams is trying very hard to make itself a platform, and it supports telephony in a way that other chat apps don't. I can be reached on my work Teams account via a dedicated phone number, and the account includes a bunch of Viva applications and pretty deep integrations with Office, SharePoint, and Power Platform.