That kind of energy is not possible for the reality stone's capabilities. The stone's power is not limitless, and mostly serves to create illusions, or to break down matter.

@WizardWarrior1 is correct. “Reality” is almost a misnomer. It took me a while to figure out how underwhelming the stone’s powers were. Probably the least of the stones, depending on the Soul Stone’s exact capabilities.

To be fair though, the Dark Elves did try to use one stone, this one, to turn the entire universe into dark matter, so it makes sense why there could be confusion on how powerful the stone is.

He established in the movie that he needed the time stone alone to make sure this event would affect everyone across the universe at the same time. As well as the others for a multitude of actions in this one maneuver.

Did they ever explain why He need the Soul Stone though? I can understand why the Avengers need them as they were bringing souls back to life but why does He need them? Couldn't he just use the 6 stones and kill half the universe?

He needed a connection with all at once. For his whole impartial move of it being random.

My assumption is that the reality stone only changes the states of matter or the composition of the environment. That's why the Dark Elves wanted to return to the dark ages, with the Aether, because it can change the conditions of the environment. The Reality Stone isn't a wish fulfilling stone, though. It can't materialize an actual infinity stone and its powers, it just changes the states of matter.

Ultimately, the full explanation is that the plot requires Thanos to get all six. And in a way I can understand that, given all six give him untapped control over the entire universe. With the Power Stone the Snap can destroy the matter of people, the Space Stone can allow the Snap to have a vast reach across the entire universe, the Reality Stone converts much of the destroyed matter into nothingness, the Soul Stone allows the Snap to discriminate living matter from non-living matter (affecting living beings through their soul, I suppose), the Time Stone maybe affects how fast or how irreversible the disintegration occurs (I'm spitballing this one lol), and the Mind Stone, I don't know.

Point being he needed all six ones to make the Snap work at a universal scale. Without all of them combined, he couldn't achieve what he did. Having only a few would limit his power scope.

I think that it's because of the power/energy the other stones have. The reality stone can only match the ability of the other stones, not surpass them, so it cant interfere with the other stones in a sort of weird sense.