It depends on context and company but in general I would avoid them the more professional the context. I work as a programmer for a pretty big company. I sometimes use them in chats to coworkers particularly if it’s just a regular conversation. We use teams and use the reaction emojis. But I avoid them in serious emails or conversations.

So I wouldn’t say they’re never to be used but in general they’re more casual. This obviously depends on company culture though. If you’re in a more casual setting or if others use them more freely then it’s probably more acceptable.