I've often wondered the same. If you have flat fields and short grass the paddock blade MIGHT be good but I'd worry about smearing and spreading shit about rather than picking it all up. And then emptying it? You still have to throw it up on the heap.
Everyone I know who's had some kind of poo vac has stopped using it as it's too difficult to operate on your own and emptying is a pain.
I like the idea of a paddock sweeper rather than hoover but again you need fairly flat paddocks and short grass. However, it's been linked to grass sickness.
Anything that spreads or potentially spreads the shit will reduce your grazing area so that type of solution should only really be used when you've moved to the next paddock.
I got a battery powered wheelbarrow, which I love. Because although you're still using a fork (I use a lightweight plastic shavings fork) you don't have to pick up and push the barrow. Emptying it is then the issue because of all the wheels you can't just aim and charge up the side of the muck heap. I still love it though.
If you have enough land, easiest of all is worm counts, rotating paddocks and chain harrowing (when hot and dry). And maybe a couple of sheep.
One other thing we used to do that actually worked well was picking by hand into rubble sacks (don't fill to the top, too heavy) and collecting those from the field once a week with a trailer. Then over to the muck heap and empty the bags on to it to reuse. Emptying the bags was a lot less hard work than using a fork to fling the shit up. That might work with an electric barrow too. Ha! I'd forgotten we used to do that!
The least backbreaking is paying someone else.