Any theory, such as the simulation hypothesis, is valuable if it helps us to accurately predict how the universe will behave under not-yet-tested conditions, and not valuable if it does not. So it sounds like the question is, can the simulation hypothesis possibly have predictive value?
If this universe is simulated, a few things are probably true:
You're totally right that those two things, by themselves, are completely uninteresting and irrelevant to us, as inhabitants of the simulated universe. Their usefulness comes from the fact that, if true, they may help us to form more accurate hypotheses about how our universe might behave, which we could then exploit to our own advantage.
In general, we assume that the universe behaves in a reasonable and consistent way. The idea that the universe may behave in an arbitrary or inconsistent way runs strongly against our intuition. When confronted with the seemingly probabilistic nature of quantum mechanics, Albert Einstein is said to have protested that God does not play dice with the universe. In much the same way, scientific hypotheses generally assume that the underlying rules of the universe ultimately are elegant, consistent, and understandable, and the fact that these are the traits we expect to find guides the experiments we perform, the data we attempt to gather, and the academic resources we allocate. If the underlying assumptions from which we derive our hypotheses are wrong, it holds back our progress.
If the universe is simulated and we do not think the universe is simulated, we will continue to devise and test hypotheses based in the idea that the universe has some single consistent set of rules. This will result in wasted time and effort as we spend more time pursuing incorrect ideas. However, if the universe is simulated and we do strongly suspect that the universe is simulated, we will spend more time developing and testing hypotheses intended to confirm or exploit the simulated-ness of the universe. For what it means to 'exploit' this property, just think about existing simulations, such as those in some video-games. In many games, the rates at which objects are grown or generated is different if the player is present in the area (and thus the simulation is simulating those things at full fidelity) or whether the player leaves, allows time to pass, and then returns (causing the passage of time and its effects to be simulated at reduced fidelity with more simple probabilistic equations). Much like individual players exploit simple simulations to achieve preferred outcomes, we as a species could exploit this complicated simulation to achieve preferred outcomes as well.
As a result, if we decide it's likely the universe is simulated, we may be able to pursue answers to these questions, which can actually be of practical value to us: - What phenomena can the universe simulate in different ways? (e.g. do high-energy matter/antimatter reactions behave differently when simulated at full-fidelity versus reduced-fidelity? If so, perhaps the energy and material outputs of the low-fidelity version of the reaction are more valuable to us than the high-fidelity version, or vice versa.) - What conditions cause phenomena to be simulated at different levels of fidelity? e.g. if phenomena get simulated at reduced fidelity only when located a minimum distance away from regions with intelligent life, then we can intentionally create those conditions if it is preferable for an event to occur in the reduced-fidelity state. Note that without the simulation hypothesis, 'proximity to intelligent life' or anything similar is a strange factor to control or experiment against, as it seems totally irrelevant on its face to how any physical reaction occurs... but if we are in a simulation that is 'about' intelligent life, suddenly the idea is plausible that events get 'optimized' into reduced fidelity based on their estimated relevance to life.
That explains why we might be able to manipulate the simulatedness of the universe. As far as the value of the simulation hypothesis itself, it can help to guide our interpretations of scientific data. If we discover phenomena that are behaving in a simplified, probabilistic way, it may indicate this kind of optimization. For example, intuitively, we expect a particle to follow a single path and to eventually end at a single position; the fact that the double-slit-experiment shows us that light particles behave otherwise could be fancifully interpreted as a universe-optimization. Likewise, quantum phenomena that are represented as probability distributions until 'observed' could be fancifully interpreted the same way. If we continue to discover such phenomena, and there are commonalities between what gets simulated at full fidelity and what gets 'optimized away', we may be able to start drawing conclusions about what the purpose of the simulation is, and therefore what reactions are likely to be optimized to save computation, and thus how we might exploit those reactions.
In the end, the value of any theory comes from how well it helps us to predict how the universe will behave. If we observe that many phenomena behave in a way consistent with the simulation hypothesis, and the simulation hypothesis then accurately helps us to predict how the universe may behave in other not-yet-tested circumstances, it is valuable.