Slack missed the pandemic zoom boom, leaving him vulnerable

Slack Technologies Inc. has been a pioneer in the development of tools for colleagues to collaborate online. When the pandemic sent millions of professionals to work remotely, other companies grabbed the spotlight, leaving Slack a potential acquisition target.

While Slack has slowly evolved into video, Zoom Video Communications Inc. and Microsoft Corp. have been among those who have reaped the rewards as video conferencing has replaced face-to-face meetings in companies.

Now,…