I ... kind of agree with the difficulty. I don't get it - DPDK is at its core really not a complex API ! Allocate a pool of buffers, and in an infinite loop, ask your NIC to fill these buffers. There. After that, yes you have to decap every packet (ethernet then IP - don't forget reassembly - then whatever you have over - UDP is absolutely no effort, TCP... not so). It's wholly manageable to anyone knowing a bit of light C++ (more C-like) and lower layers (and can parse the sometimes very dry and cryptic doc, for all the utility fonctions. Interaction with the actual consumer of the data can be done with DPDK-provided primitives or simple shared memory... it's really not hard for a mid-level systems programmer. But I still find myself unable to hire people who can work at that level of the stack, a bit baffling. I can't see how they'd be better with io_uring or AF_XDP and all their inherent complexity. Anything harder than a socket and epoll and you're a wizard now...

One other big plus of DPDK for me is the low-level access to hardware offload. GPUDirect (when you can get it to work), StorageDirect or most of the available DMA engines in some (not so) high-end hardware. The flow API on mellanox hardware is the basis of many of my multi-accelerator applications (I wish they supported P4 for packet format instead, or just open-source whatever low-level ISA the controller is running, but I don't buy enough gear to have a voice). Perusing the DPDK documentation can give ideas.

So, yes, very low-level with some batteries included. Good and stable for niche uses. But far smaller hiring pool (is the io_uring-100Gb pool bigger ? I don't know).