The screwy concept in “Why does anything exist at all?” is not existence, it is “why.” There’s nothing wrong with “why” as such, it just doesn’t apply to existence. That’s what makes for wrong questions: pairing up words that don’t apply to each other, such as “What is the sound of blue?”
“Why” only applies when there is an alternative that could have been, but nothingness can’t be (as soon as it tries it becomes something) so there’s no alternative to existence.
The screwy concept in “Why does anything exist at all?” is not existence, it is “why.” There’s nothing wrong with “why” as such, it just doesn’t apply to existence. That’s what makes for wrong questions: pairing up words that don’t apply to each other, such as “What is the sound of blue?”
“Why” only applies when there is an alternative that could have been, but nothingness can’t be (as soon as it tries it becomes something) so there’s no alternative to existence.