Why have Muslims abandoned I'tikaf, even though it is a prophetic Sunnah, and what is its purpose?

I'tikaf (spiritual retreat) is a confirmed Sunnah (definition) that the Messenger of Allah, peace and blessings be upon him, regularly observed. However, it has disappeared from the lives of Muslims for several reasons, including the weakening of faith, indulgence in worldly pleasures, the low regard for Paradise, and confining the love of the Messenger of Allah, peace and blessings be upon him, to mere verbal expressions. Some of the early Muslims (Salaf) were astonished by people abandoning I'tikaf, despite the Prophet's consistent observance of it.

The I'tikaf that the Prophet, peace and blessings be upon him, consistently observed in the latter part of his life was the I'tikaf of the last ten days of Ramadan (definition), which serves as an intensive spiritual training course. The primary goal of his I'tikaf, peace and blessings be upon him, was to seek Laylat al-Qadr (the Night of Decree), as he began seeking it in the first ten days, then the middle ten, and then was informed that it was in the last ten days.

Among the benefits derived from this Hadith (definition) are: the Prophet's diligence, peace and blessings be upon him, in seeking Laylat al-Qadr; the Companions' following his example; and the Prophet's compassion, peace and blessings be upon him, towards his Companions.

I'tikaf has other objectives, including: withdrawal from people and finding solace in Allah; rectifying the heart by turning to Allah; complete devotion to worship; preserving the fast; and reducing involvement in worldly matters.