USA here - I work for a fortune 500 technology industry company...We use MS Teams internally for most stuff, mostly use MS Teams for organized conf calls internally and with customers, and then use regular text messaging for one-off messages with each other and customers. We don't use whatsapp at all for anything - I am pretty sure I don't even have a whatsapp account.
None of my friends use whatsapp either. I communicate with most of my friends and family via text message, a few of my more paranoid friends will only chat via "Signal", and then for bigger group chats we use Discord.
Unfortunately, after you eliminate all the collab services blatantly handing their data to government-backed built-in spy services, and all the services with off-shore backend servers, and all the services with poor track records for security, MS Teams is one of the only options left...as shitty as it is. Our customers insist on it, so we bend to their will.