

No, unlock as in: You can install whatever operating system you want. No need for “jailbreaking” on Google phones. They officially support unlocking the bootloader (and re-locking it later as well!). There are many things not to like about Google, but how they handle their phones when it comes to openness is certainly not one of them. Pretty much all other phone vendors are much worse than that (except for maybe a few small ones like Fairphone).
That’s not what you were saying. You were explicitly talking about Google. Also, implying it is Google’s fault that other manufacturers don’t let you install other operating systems easily is pretty bizarre. If you want to complain about that, at least complain about the right companies. Those are usually the phone manufacturers and/or the SoC manufacturers. The SoC manufacturers often times are particularily problematic, since they often do not publish open source drivers at all or in a very limited fashion.