Off of the top of my head, torture and similar very unpleasant things are useful for at least two purposes.

As in this post, you could attempt to quantify how much you value something (in this case, effective immortality) by how long you would be willing to exist in an extremely uncomfortable state (such as being tortured.)

Similarly, if someone is attempting to make certain absolute statements (such as "I would never kill another human being.") regardless of circumstance, such conjecture can be used to quantify how much negative utility they attribute to committing such an act.

If you feel severe discomfort in being in a conversation where someone is using torture as a hypothetical, I suppose that you could either leave the conversation or ask them to use a different hypothetical, but the whole point of using torture as a hypothetical in such a case is because it is extremely unpleasant, so their alternative, if chosen well, maybe be equally discomforting to you.