Aristotelian physics is simpler than Newtonian physics, which is simpler than either relativity or quantum mechanics, both of which will probably turn out to be simpler than whatever theory we come up with that somehow encompasses both.
Chapter 1 of the Book of Genesis is shorter than On the origin of species, which in turn is shorter than the shelf-full of books you would need to cover all the details Darwin didn't know about.
The truth does generally turn out to be simpler than its alternatives, when you fill in all their details and add the epicycles you need to make them consistent with what we actually observe. In some sense that's how we recognize the truth: it's what you don't need to keep making increasingly implausible excuses for.
But it's not reliably "very simple" if that means "short blogpost length at most", and things that purport to be that simple often turn out to be simple only in appearance. (Like saying "a witch did it", which in some sense can explain anything, and for the exact same reason explains nothing until you've filled in lots of details about what witches can do and how, at which point it stops looking like a good explanation for anything.)