[hot_gril]

It's not the pointers themselves so much as what they're typically used for. How would you do dynamic sizing? Imagine sending just a struct of integer arrays this way, you'd have to either know their sizes ahead of time or just be ok with sending a lot of empty bits up to some max size. And recursive structures would be impossible.

You could get around this with a ton of effort around serdes, but it'd amount to reinventing ASN1 or Protobuf.

[nly]

A lot of protocols in low latency trading systems just have fixed maximum size strings and will right pad with NUL or ASCII space characters.

Packed structs with fixed size fields, little endian integers and fixed point is heaven to work with.

[hot_gril]

I can see that in niche situations, particularly if you have a flat structure and uniform hardware. Cap'n Proto is also a way to do zero-parsing, but it has other costs.