while abstraction has parallels to a variety of real-world things, i think that attempting to view it as a one-to-one parallel for any single thing ignores its multi-faceted nature, and ultimately ends up producing relatively weak readings of the text.
the most obvious comparison is taking one's own life. this is the way it's largely framed in-universe, and the way that the characters seem to think about it. people only do it when their mental health is at a breaking point. neither we nor the characters ever witness it happening - it's something that people only do when they're alone. those who remain stable hold funerals for those who've abstracted. and of course, there's the phrasing of Jax's final words.
while this reading is straightforwardly supported by the framing the characters give the events, attempting to read it exclusively through that lens results in contradictions that are too significant to prevent the reading from being completely accurate. most importantly, we know as soon as we've seen Queenie post-abstraction that the mind of someone who's abstracted isn't gone, it's just altered. an abstracted individual isn't able to communicate, nor are they able to act as they once did, but them or some part of them is still there. in this way, i think it's also analogous to having a disability, particularly one that makes the disabled individual be seen as "not valuable" to society at large.
the circus is structured around being able to participate in, and derive enjoyment - or at least socialization - from Caine's adventures. anyone who isn't able to do that is not considered to have worth, and seen as a problem to be "fixed," which we see firsthand in Caine's psychologization of Zooble. in this lens, abstraction is also a social death, as someone's who's abstracted is structurally prevented from participating in adventures. we also see this in the fact that other people avoid people who've abstracted. that social death is then compounded by the fact that Caine sends abstractions to the cellar, where they cannot be seen by others or interacted with. i see this as transforming that social death into something closer to a physical death, as the abstractions are quite literally buried and made impossible to interact with again, even if others might nominally want to do so.
thus far, i've been focusing largely on the mental effects that abstraction has on the abstracted. this is not to say that the physical effects - the corporeal transformation - associated with abstraction is insignificant. this transformation is a physical disability in its own right. however, i think fully understanding abstraction requires recognition of the fact that it is neither solely a physical disability, nor a physical disability that is decoupled from the mental disability. if it was either of those, it would be something that Caine would be able to fix, given the degree of physical manipulation he's able to exert over others. he himself says that he doesn't have that level of control over minds - and as much as he's shown to be an unreliable source in that he does have some control over minds that he is unwilling to admit, i believe he's at least mostly telling the truth here. throughout the majority of the show, his central motivation is shown to be to keep as many human minds as possible as engaged as possible, so i believe he would choose to reverse abstraction if he was capable of doing so. given all that, i think it's most accurate to say that the disability associated with abstraction is one that starts as a mental disability, and then subsequently and additionally asserts itself as a physical one, while remaining inextricably linked to the mental aspect.
tangentially, i also find it interesting that abstracted individuals tend to be aggressive when in well-lit spaces, and calm or even sleepy in dark spaces. i think it's likely that this aspect is also an important consideration for a full understanding of abstraction, although i don't have enough to say about it myself to incorporate it fully. the most concrete thing that i think i can say here is that, to me, it suggests a potential altered emotional response and difficulty with expressing emotions other than anger. the emotional response seems easy enough to understand as a reaction to the mental and physical trauma associated with abstraction, but i'm not entirely sure what to make of the fact that darkness is soothing to abstracted individuals.
in all of these readings, i think it's important to recognize how the circus becomes a more kind and equitable place for the abstractions after the finale, and how that reflects on the real-world parallels of abstraction. that kindness is a fond remembrance and a compassion for those who've passed, rather than sending them away to never be thought of again. it's accommodation for the disabled, even when that disability is so extreme that it prevents the disabled individual from interacting with others in a normative way. it's acceptance that being "fixed" is not always realistic, that being "fixed" isn't and shouldn't be a requirement to not be cut off from social contact. it's a hope for a more empathetic world.