In my younger days I thought direct democracy was unworkable, but now I realise that might have just been my brain conforming to the bourgeois representative government status quo.
Obviously we easily have the tech to do DD these days, everyone has a smart phone in their pocket, we could do it instantly and on the go. But how you could manage a planned economy that way I’m not sure.
I'm convinced that dd is the only ethical way personally
the practicalities are a false question imo - we have been capable of dd since the dawn of civilisation, it is a matter of political choice and time/resource allocation, not a technological barrier.
representative democracy is a sham - you as an individual cannot be represented by another in politics, as politics is the art of choosing your destiny.
my idea of dd would be like an hourglass - as issues become more pertinant to you as an individual, the greater your ability to steer your destiny (i.e. the more involvement in democratic decision making). Since local issues will concern you and your life more directly, dd would work on a local issue with for example a small community forming the democratic committee deciding on the design and placement of a local park, or the exact implementation of some project decided at a greater scope. An issue a town over may not affect you, so you may not have a vote or say on it (at least directly). As decisions become less spatially/socially (locally) relevant to you, you stop having such a direct say over them. Of course, as issues become bigger in scope and affect more people, more people need to be involved. So these grand decisions that we have no say in now, such as resource allocation/production, infrastructure, R&D, military activities, social projects such as housebuilding and education (and are instead left to our representatives, or even orgs/bodies with no representative oversight), would instead be decided upon by everyone that the issue could concievably affect.
it would as a system require a great deal of thought and careful implementation, but that is the case with all good things, and once people can steer their own destiny, bound ofc to the destiny of others as is the nature of society, i believe that we would see a rapid evolution & advance in the art/technology of politics. Instead of our destiny being steered by a few parasites, which impedes our social/political development, it would be steered by all for all. So that the system of dd will by nature improve itself and find its best form.
And ultimately the greatest decision making body (making decisions on stuff like world economy, space programmes etc) would be all of humanity in a great congress or committee, deciding on the destiny of our species.
as for the practicalities - planned economies etc, if we were to plan an economy for the world, why not involve everyone in the world in the plans? It may be a slower or in some ways less efficient process, but the plan will naturally be vastly better than one or a few individuals may devise.