sleepy It's a good idea to give a look at the GrapheneOS website. Specifically the prerequisite section of the installation guide where it says "To make sure that the device can be unlocked to install GrapheneOS, avoid carrier variants of the devices. Carrier variants of Pixels use the same stock OS and firmware with a non-zero carrier id flashed onto the persist partition in the factory. The carrier id activates carrier-specific configuration in the stock OS including disabling carrier and bootloader unlocking. The carrier may be able to remotely disable this, but their support staff may not be aware and they probably won't do it. Get a carrier agnostic device to avoid the risk and potential hassle. If you CAN figure out a way to unlock a carrier device, it isn't a problem as GrapheneOS can just ignore the carrier id and the hardware is the same."
https://grapheneos.org/install/web#prerequisites.
Verizon has been heavily discussed on this forum with regards to the company locking their device's bootloader and there not being a way to undo it. A simple search of this forum will bring up said discussions.