I also have a “Done” column, which is arguably pointless as I just delete everything off the “Done” column every couple weeks,
Having a “Done” column (or an archive board) can be very useful if you want to see when was the last time you completed a recurring task. It helps prevent tasks with long recurrences (quarterly, biennially, etc) from falling through the cracks. For example: dentist appointments. They’re supposed to happen once a year. And, ideally, you’d create a task to schedule the next one immediately when you get back from the previous one. But let’s say that doesn’t happen. You got distracted, there was some kind of scheduling issue, life got in the way. Then, months later, you wonder, “Wait, how long has it been since I’ve been to the dentist?” Archiving completed tasks instead of deleting them lets you answer that question immediately.
Having a “Done” column (or an archive board) can be very useful if you want to see when was the last time you completed a recurring task. It helps prevent tasks with long recurrences (quarterly, biennially, etc) from falling through the cracks. For example: dentist appointments. They’re supposed to happen once a year. And, ideally, you’d create a task to schedule the next one immediately when you get back from the previous one. But let’s say that doesn’t happen. You got distracted, there was some kind of scheduling issue, life got in the way. Then, months later, you wonder, “Wait, how long has it been since I’ve been to the dentist?” Archiving completed tasks instead of deleting them lets you answer that question immediately.