Yeah power consumption (and performance per watt) is the main reason I keep buying Raspberry Pi, I haven't find anything similar on that regard, specially for pi zeros

It's also very hard to encounter x86 machines that can be powered from PoE.

I'm on mobile so can't easily pull up an example part number, but digital signage controllers can often be PoE powered. They're insanely overpriced new from the actual suppliers, but for hobby projects they can normally be sourced relatively easily on ebay. The trick is that many of the ebay sellers don't bother listing the specs, so you need to first search digital sign cintroller/computer on ebay then look up the spec sheet from the model number.

Another annoyance is that you need to buy a hat for PoE, it seems like an oversight

I really like the ecosystem around them. All of the nice compact hats, the software, the 3D print files. Very googleable which also means easy to get help from an LLM.

I thought x64 was better for perf per watt just because perf is so much better