I think the overhead is protobuf itself but I can't check.
Comparing a wrapped C++ gRPC backed stack with an httpx/requests backed one is like comparing apples to elephants.
Protobuf simply encode things way more efficient that JSON can define a single object. You're quite frankly spewing bullshit in this whole thread.
Comparing a wrapped C++ gRPC backed stack with an httpx/requests backed one is like comparing apples to elephants.