He wasn't gifted anything.

The article is loosely worded but what happened was that first he invested 3 months of his time (while holding other jobs to support himself) into Winchell's training program.

Winchell is a franchise of donut shops. I don't know what the deal was back then, but today "Winchell's has a franchise fee of up to $0, with a total initial investment range of $3,400 to $44,700"

https://www.franchisegrade.com/franchises/winchell-s

His first donut shop was a Winchell franchise. A franchise is not a gift. He had to work hard, make the business profitable and pay back portion of the profits back to Winchell.

He became rich by extremely hard work, saving all his profits and re-investing them into opening more donut shops.