"Reviewers largely see Slack as the default hub for team communication: fast, clean, easy to adopt, and especially strong for channels, threads, file sharing, search, and broad integrations. Many say it replaces internal email and works especially well for remote, async, and startup teams. The main complaint is noise: too many channels, notifications, and buried threads can make it overwhelming without strong team discipline. Some also mention shaky huddles or video, occasional lag, search gaps, onboarding complexity, and limits or cost that sting smaller teams."