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.
Any kind of centralized system of power, including whatever apparatus is used to implement democracy, can be used to gain and consolidate power. In the long run we need to find ways to dismantle these systems (without leaving a power vacuum) or they'll just generate new class struggles.
The fact that direct democracy doesn't scale very well past the size of a workplace or local community might actually be a feature.