The simulation hypothesis is in principle testable in that, if we were in a simulation, we may be able to find bugs in it, possibly even escape the sandbox. Right now, we don't have any "angle of attack", and nothing we could suspect of being a bug (which includes e.g. being able to perceive artifacts of some optimization in the simulation) - so there's no point in working oneself up about this, or assuming it's true. However, because this is testable in theory and there's a possibility it'll become testable in practice, it doesn't qualify as fundamentally "meaningless" in my book.