Asgard has never had a plethora of space-faring ships. We tend to prefer the Bifrost. So that I do not have in my possession, my friend.
There is certainly restlessness. There are many here that have come from primarily interworld existence.
But, the Tesseract seems intrinsically unstable in keeping you here. Some have been here for over two years, others have left after a matter of days, quite without warning.
I arrived via the Bifrost, not through the Tesseract, so the Asgard knows where I am. For those through the tesseract the predominant theory is that they are taken and returned instantaneously with no memory of being here, nor absence marked by their comrades.
I am uncertain quite how that works, but my lady is a physicist, and wise as Saga. She studies the Tesseract and might better be able to answer you.