What Google Apps can i delete data from safely?

I got was what I thought was a 4 GB phone. More than half of that was a flat out lie as they were system files.

But the other half is constantly choked up on Google programs. I don't understand why I need Google App, Google Play Services, Chrome, Maps, Gboard, Google+, Google Drive, Google Music ...

Well, yes, I know what Google says I need Google Play Services for - to make sure everything else is interconnected without the need to wait for a total android update, thank you very much Google.

But of the less than 2 GB I have available, these Apps are taking up virtually all of the memory on my phone. For the biggest Apps, about half of the space is taken up by data.

Since Google has told me everything Google is interconnected and if I clear the data from one App it may negatively affect the performance of everything else on my phone, I have no idea what I can delete and what I can't delete.

This is going to become a severe problem soon, because all of these Google services will run out of memory space to put their data in. So something needs to be deleted from some Google App to make space for whatever other Google App is more important.

I tried inserting a memory chip into my phone, and that's pretty much useless as none of the Google Apps will store any data there.

Can someone please let me know what data can be deleted and what data can't be deleted? Or tell me if Google has effectively made my phone obsolete because I demands more memory than my phone has?