Video: G Suite vs Slack

Get business email, video conferencing, and cloud storage from Google. All you need to do your best work, together in one package that works seamlessly from your computer, phone or tablet. If you are looking for self-hosted G Suite alternatives pay attention to Microsoft Office and ONLYOFFICE.
Slack brings all your communication together in one place. It's real-time messaging, archiving and search for modern teams. Create open channels for the projects, groups and topics that the whole team shares. Slack searches whole conversations, not just individual messages, so you can find what you’re looking for no matter who said what or when they said it. Slack free open-source (self-hosted) alternatives are: Mattermost, Rocket.Chat, Zulip
Face to face in the news:

2016 - G Suite adds Slack integration to fight Slack

Google has added Slack integration for Google Docs and Drive in G Suite. It allows users to bring files from Drive directly into a Slack conversation. They can also create new Docs, Sheets and Slides files right from Slack. Every Google Drive file you share in Slack is automatically indexed and searchable, so you can tap into your team’s collective knowledge and quickly find past conversations and files.