Food nets could help some people depending on their physiology. But I saw a YouTube short a few days ago about fold up seats ANA has in A380 Economy that are ... effectively what Air NZ has as their Skycouch.
While practically dying in a Qatar 777 in economy last week, with old mate next to me taking up about 25% of my personal room (*ahem* I digress) ... I got thinking.
I'm tall - 194cm. And I struggle with a sciatic nerve in my leg that gets really uncomfortable after like 5 hours in the air. Aside from standing up, not much helps me. If I get an aisle seat, I can stretch my leg a little. It mildly alleviates symptoms. But it's no cure. My butt and top of my femur are still getting pressure on them, so the nerve hurts.
About the only seated position that helps is propping my leg/s up against the back of the seat in front of me, or trying to put my leg on the edge of the seat (but the fabric is usually slippery, so that doesn't work). My butt still has pressure on the seat, but my leg doesn't anymore.
Seeing those lifted leg rests on ANA and Air NZ, I wonder what the feasibility would be of having all economy seats like that. It would add weight to the aircraft. But it would allow all people to shift their positions during a flight - not only as a lie-down option across a row, but in individual seats. It would relieve pressure points on the back and legs.
With Emirates teasing a whole new way of looking at economy, I wonder if something like the above would make it more comfortable, without changing layouts and decreasing seating numbers.