Subjective experience has a pretty clear meaning. Cogito ergo sum. Unless you're a panpsychist, it is assumed that things like people have subjective experience and things like rocks don't have it. We don't have a causal explanation for subjective experience, but there's absolutely no reason to believe that computer programs have them any more than rocks. In fact, a rock is actually more likely to have subjective experience than a LLM since a rock at least has a temporal identity, LLMs represent a process not an entity.
I have no problem saying a tape recorder has subjective experience: it's subjective (the recordings it makes are its own), and it experiences its input when its been commanded to record, and can report that experience when commanded to play it back. Note this does not mean I think that a tape recorder can do anything else we humans can do.
What is being experienced (recorded) is not the process of experiencing per se. Most people don't separate the two, which leads to endless disagreements.
But yes, a computer program by itself can't have subjective experience. Nor a rock. At least until it weathers, gets turned into a silicon, and into a computer to run that program. Then it's all information processing, for which subjective experience is trivial.
