To add to that other (much more in-depth) comment, I remember reading on the GrapheneOS FAQs that disabling everything you’re not actively using will generally improve security as you’re reducing the number of potential ways for an attacker to get in (phrases like “attack vectors” and “surface area” were used).
On a separate note I didn’t even know 2G towers were still active anywhere; they’re shutting down the 3G ones here!