For sure cut down code complexity for the single clever code writer who wanted to be fancy. Not so sure about all the readers that will come afterwards.
Not at all. I often have to slurp in large amounts of data to be processed in some way. If you don't want to use huge amounts of memory for doing so, you either need to (a) write some horribly obtuse code or (b) use coroutines. Coroutines allow you do this in a more natural and composable way.
Anything involving a lexer and parser is a good example of this, and exactly one of the use cases given in the example. With coroutines, the lexer can take some input and emit a series of tokens which the parser can consume on the fly without any need to do any complex interleaving of the parser and lexer code. You also gain the ability to stop lexing early in case the parser encounters an issue.
I'm not sure what kinds of software you work on, but this is little more complicated or clever than Unix shell pipelines.
Anything involving a lexer and parser is a good example of this, and exactly one of the use cases given in the example. With coroutines, the lexer can take some input and emit a series of tokens which the parser can consume on the fly without any need to do any complex interleaving of the parser and lexer code. You also gain the ability to stop lexing early in case the parser encounters an issue.
I'm not sure what kinds of software you work on, but this is little more complicated or clever than Unix shell pipelines.