I've taken quite a bit of time off between jobs and lived off minimal savings (over a year several times now) and I've experienced exactly what you describe - the boredom and depression. However, I also came out the other side and now I wish this for everyone.
The boredom and depression was because I was operating from the typical mode of being where there was a belief that my only value was that which I could provide to society. This was a belief that's indoctrinated in us from a very young age - through school, grades, parents, and work.
Once this belief fell away, a new kind of motivation has opened up - the curiosity I felt as a kid to create and explore and experiment and follow my interest. The joy of simply being alive, being allowed to live this life without having to perform for anyone, force a persona, or act a particular role.
The thing is, to lose that belief that only a job/work/career can provide us fulfilment, you have to be willing to go through and sit with the depression and grief of realising that that belief was a lie all along.