Slack and Teams usage among startups and AI companies

A commenter says they don't know a startup or “serious tech company” using Teams, claiming those companies use Slack and naming Cloudflare on Google Chat as an exception. In a follow-up, they list OpenAI, Anthropic, Meta and Cursor (“pre-SpaceX”) as Slack users, question a chart's origins and speculate that it may reflect non-tech companies.