Is this in Y+ or domestic J?
10cm?!
In Y there's no way I can read or watch TV, there's the physical space for it but the angles you're forced to view at don't work. Maybe if I could remove my eyeballs. Eating is possible but not exactly great, you can't lean over the little foil thingy while eating because that's where the seat in front is, so you either hold the foil thingy up to your chin or run the risk of drips/crumbs down your shirt (singlet if flying JQ).
Reclining also cuts into already-at-a-premium knee room, and then me reclining just pushes my knees further forward. They're already lightly wedged into the seatback in front, now the wedging has more force. And I'm only 6'2", getting close to average these days.
Maybe things are better on more modern international-spec aircraft these days? I've not been in Y long-haul for a decade now, my recent Y experiences have been QF A330-200 to Singapore (old interior) & domestic configuration (domestic flights or to NZ).