It's a difficult one- my garden has been transformed this year and the amount of soil that came out of here was several tonnes and it does come down to the question of available space.
Fortunately there was a place of unused space available to me- it was also the space that I managed to deposit many of my unwanted plans/shrubs into.
Garden outside the garden.
I would agree with others, that unwanted soil is something you can do so much with.
I've used some of the unwanted turf to create tumbts, so creating a variation of height, as well as filling some pots. I've also sieved a lot of it and used it as a bottom level for seeds. Great ideas re raised beds. it has so many uses,