I am the author of https://Nestful.app (there's some overlap, but we do not seem to compete). I have built it after being through the same ordeal, and have come to the conclusion that the tool is not the main hurdle, especially at the level of Trello or Asana, which are very high quality tools.

The lack of productivity comes from the methodology those tools implement. Their methodologies contributed a whole lot but by now we are used to that contribution, and so we must advance it.

Nestful implements a methodology I call "spontaneous productivity". In which there is no planning. Nestful will tell you what is the next thing you need to do, and that is it. Currently you have to know the methodology very well and "do it by hand", but I am very close for a smooth UX.

Either way, my point is that improving upon Trello or Asana is like honing a sharp sword. At some point, we need to switch to a gun.