I’ve had numerous root canals as well as extractions (in my younger stupider days). I should have had rc on the extracted ones but it wasn’t offered as an option nor explained.
In addition to preserving the base of the tooth below the gam in order to support a crown, a rc prevents your other teeth from drifting into the vacant space from an extraction and unbalancing your whole jaw and bite.
What flew across the room was, in all likelihood, the crown and not the tooth. Presumably the dentist could have reattached it for considerably less money than creating another one.
Crowns are usually made of durable stuff as well as bring custom fitted. Flying across the room and bouncing around a little shouldn’t really do any significant harm.
And, as Gail advised, teeth with crowns need to be treated carefully when flossing lest you unintentionally hook the floss around the bottom of the crown. If you pull hard enough it will go flying out of your mouth.
But it still beats dealing with dentures and Polident and all that crap :)