That's just the HN/startup echo chamber doing its thing. Out there, MS's offerings have never been stronger for small/medium businesses.

IIRC sometime last year teams passed slack for daily & weekly users pretty comprehensively.

Office 365 is heading close to 200m users. Slack and Teams use is both in the low 10s, but teams is growing fast into that 200m since it is bundled and interacts with the other parts.

Slack is getting eaten by both the top and bottom.

From the top, Teams has been effective in beating Slack, especially with Office 365 subscribers.

From the bottom, Discord is doing a pretty decent job.

Slack is increasingly stuck in the messy middle.