Originally Posted by mce

Gmail → Fastmail → Self-hosted (via Cloudron)
Google Contacts → Fastmail → Nextcloud Contacts
Google Calendar → Fastmail → Nextcloud Calendar
Google Search → Bing → DuckDuckGo
Google Maps → Bing Maps → OpenStreetMaps and OsmAnd
Google Analytics → Matomo Analytics
Google Drive → Nextcloud Files
Google Photos → Nextcloud Files/Gallery
Google Docs → Collabora Office (Nextcloud integration) and LibreOffice
Google Play Music → Spotify / Plex → Spotify / Jellyfin
Google Play Movies/TV → Plex → Jellyfin
Google Play Audiobooks/Books → Audible/Kindle
Google Play Store (apps) → F-Droid / Aurora Store
Google Android → Lineage OS → Ubuntu Touch on PinePhone (coming soon?)
Google’s Android Apps → Simple Mobile Tools
Google Chrome → Mozilla Firefox
Google Domains → Hover
Google Hangouts → Matrix and Nextcloud Talk
Google Allo → Signal
Google Podcasts → PocketCasts → AntennaPod
Google Newsstand → RSS
Google Wallet → PayPal and Cash App
Google Voice →Ting Mobile