Update:
1) Google collects your location with Android, even if you disabled it in the system settings;
2) Facebook (and Google) access to your contacts and use it to make networks;
3) you may give granular permissions to Facebook and Google by rooting your phone and installing a ROM such as Lineage OS or Replicant; and
4) in my country, France, the law allows me to ask them to delete anything I want.
If you want both privacy and security you may want to have a look at these links:
1) Blackphone: https://www.styxblackphone.com/buy-blackphone
2) BSD-based secure phone: https://hackaday.io/project/13145-bsd-based-secure-smartphone
@wire I follow another project aiming to design a phone. The focus is not at first on privacy and security, but since it is open-source, and partially open-hardware (I'm not sure exactly, but it is mentionned that the connectors all have open-source software). And this phone will quite cheap, although not featuring everything that a smartphone has, it is more than a "dumbphone" : https://hackaday.io/project/19035-zerophone-a-raspberry-pi-smartphone