I can’t remember the name, but we have ships designed to rescue submarines from that depth with essentially a long ass crane. I don’t know of they still exist, but America did it to recover a soviet(?) Sub that fell to the bottom of the ocean.
Either way there’s no way they have enough oxygen to last much longer unfortunately…
Recently bough an e-ink reader for this exact reason. I’m reading for the first time in almost 10 years and I am falling asleep way quicker and getting better sleep than i have in a loooong time. Best $100 ive spent in awhile.