there is no doubt that a "nursery"-like construction can be implemented in Go in the same way like any language with "goto" can implement structured loops. The point is in constraining what can be done.

There is a trade off: "goto" is powerful but it is likely to lead to a spaghetti code. "nursery" introduces constrains but makes it easier to deal with error handling/cleanup, back pressure issues such as https://lucumr.pocoo.org/2020/1/1/async-pressure/