If a bagel didn't have the hole, to lessen the distance that the heat must penetrate to cook evenly all the way through during both the boiling and the baking, it would be a mass of raw yeasty putty in the center¹ - - - or would have a such a hard shell² it would require paving tools to break it open - - -

unless it was made so thin that it would be a Tortilla.

It is quietly rumored that some "commercial producers" omit the boiling. A young Jewish classmate explained, many years ago, that one should not openly accuse them of this, as a sacrilege of this order would demand a public stoning - - - hence it should be left unsaid.

¹ A "chewy" center is favored by many, but in a mediocre bagel it's common to find the center almost completely uncooked. People who've never had a proper bagel may develop a liking for the raw yeast flavor and tile grout texture.

² An excessively hard "shell" renders the product unfit for much of anything other than crushing for use as road gravel. Some like at least a "skin," but in families where there are elders lacking teeth a separate cooking of "soft-shells" may be appropriate.

Most commercial bagels should just be called donuts.

John