Gmail -> ProtonMail free tier Google Maps -> Open Street Maps (although I personally use Ordnance Survey Maps) Google Docs -> I use LibreOffice because I don’t need the cloud functionality Google Calendar -> I currently use a Synology NAS to host my own but I’m eagerly awaiting the release of Proton Calendar

As a disclaimer to this I actually pay for ProtonMail and OSMaps because they’re products I use daily and feel that they deserve the money, however they do have free tiers and there are free alternatives to most Google software. I’d strongly suggest looking into de-Googling, there’s an entire subreddit dedicated to it.

Literally every service the previous poster mentioned has an ad free/ tracking free alternative which ships with the iPhone. Aside from that, there are too many "free products" without advertising to list them so you'd need to be more specific.

Most OSS I suppose.