No. I'm on GrapheneOS and not tied to Google.
You must be thinking of the Google Play Services but these aren't required by GrapheneOS.
As long as it depends on Google paying upstream development that GrapheneOS updates from, it is tied to Google.
Now if GrapheneOS was its own thing without additional AOSP code updates.
It is tied to google inasmuch all target phones are google branded. https://grapheneos.org/faq#supported-devices
Hopefully that can change, in the future
Anyone on Graphene is tied tot Google, for it requires Google hardware.
No, we're thinking about the fact that Android is Google owned and developed and no removal of Play Services changes that.
Every Android ROM is critically dependant on Googles work to actually develop and secure the OS.