the first theory I came up with is that god either attempted suicide or comitted it, my reasoning for this being that in Testament VIII (or Testament 8), god says

I CAN'T TAKE ANYMORE OF THIS GUILT AND REGRET , FOR ME THERE IS NO TOMORROW . . .

I AM HOLLOW

. . .

I BEGAN TO SEEK THE END OF MY DAYS .

BUT WHEN I STARED INTO THE ABYSS . . .

THE ABYSS AVERTED ITS GAZE .

which implies god, (assumably) the person writing the Testaments, attempted suicide, and possibly succeeded (however we'll only find out when 8-S comes out)

my second theory is that when you P rank all of the Prime Sanctums, you'll be able to find a secret exit in P-3, which leads to P-P or P-S, and that the Prime Soul in P-P is god himself after commiting suicide

my third and final theory is that since the place 7-S takes place, the Library of Babel, was made for people in the Violence layer who want a break from the bloodshed and just want a bit of peace and quiet