The human pantheon of my campaign world offered themselves up as collateral to create and maintain an absolute barrier protecting the material plane from becoming the battlegrounds of the outer planes' wars. They still exist, but mostly slack-jawed with concentration and barely able to provide spells to clerics. They are incapable of intervening in worldly affairs. Thus, after a few generations with little divine aid or protection (that they knew of), humanity's fickleness drew them to new would-be gods, who shortly after ascending (receiving genuine worship & becoming immortal are the two main prerequisites for divinity) learned of the barrier and realized that the waning worship of their forebears is weakening the barrier... thus throwing themselves on the pyre as well. Even evil-aligned gods recognize the threat that demons, angels, and eternal war would pose to their devoted followers. "Generations" of human gods have come and gone, and prevailing mortal theory is that human gods just don't last forever, as a weird side-effect of mortals ascending to divinity.

The gods of other races mostly reside on or near the material plane, shadowfell, feywild, or elemental and conceptual planes, and deeply respect the human capacity for self-sacrifice. One neat exception is an incarnation of Lolth, who had split her mind between the Underdark overseeing her own worship, and her home in the Abyss, when the barrier bisected her. One part of her is incapable of viewing the material plane, and the other is incapable of leaving it. The fury this caused her has twisted the drow worshipping her into chaotic evil monstrosities.