Except that’s not actually how it worked. We didn’t always have solid scientific models before things happened. Bicycles are the more famous example of something that existed for years before science could explain why it works, it’s still not perfectly explained. Flight is also somewhat week in the scientific model for lift, but we can still make planes.
While there have been instances where scientists have theorized/discovered X is possible and then a way to do X was built, it’s not required.