Basically this is done to ensure that the phone isn't locked by the carrier, meaning if you buy the device directly from google you can still unlock the device by connecting to the internet. Yeah, it sucks, yeah, you own your device less in a way, but im happy they still let you do it.

I sent a support message a while back asking about it on the google store thing - and they said it was unlocked. I installed grapheneOS today on the pixel 7 actually, and was surprised to read that you had to connect it to the internet just to unlock it. Its strange.

I enjoy grapheneOS so far though.

Edit: if you get the phone through an upgrade with your providers plan it will most likely be locked. There are some threads on grapheneOS' forum about which ones do or dont lock the phone.