Does not scale well for people who juggle lots of tasks

While Todoist is good for simple sharing, it lacks support for some basic features handled by other task managers: features essential for people who juggle lots of projects. Chief among these is the lack of separate "start" and "due" dates for every task. Without this, it is impossible to easily prioritize what tasks need to be worked on except by setting the "due date" to "today" even if it isnt due for several weeks. For instance, taxes are due on the 14th, but you want it to appear in your "today" menu at least a week before that, so you have to set the "due date" to the 7th. But lets say you have a report due on the 7th as well. Todoist cant distinguish between these two cases, but many other task managers can. Todoist gives lip service to GTD but central to GTD principles is the ability to focus on what is important. The above is just one example of where Todoist fails where other apps succeed. Over time these problems added up, finally driving me away from Todoist altogether.

Luhmann about Todoist: To-Do List & Calendar, v6.3.18