I must be lethal because I've killed a few of these "hard to kill" plants and the latest casualty is the plant whose photo I have posted here... or rather, what remains of it.
I was checking my plants and saw that this particular one had root rot - the root just melted in my hands, it was already hollow (seems like it rotted and then dried out) so I tried to salvage the 1 remaining leaf by cutting it up and then planting it in soil. Hopefully, these cuttings are still strong enough to propagate.