I just don't believe you. My CPU doesn't understand Apache Arrow 3.0.
Incorrect. Only Arrow Flight embeds the Arrow wire format in a Protocol Buffer, but the Arrow protocol itself does not use Protobuf.
Sadly, the latter isn't (yet) well supported anywhere but Python and C++. If you can/do use it, though, data are just kept as as arrays in memory. Which is exactly what the CPU wants to see.