Meaning of "money leaving the space for lower-hanging fruit." in the context of economics

To be more precise, I copied the whole sentence here. Can you understand the following sentence? if u do, could u please explain what "money leaving the space" means in it.

That's really the driver that seems to be the culprit in money leaving the space for lower-hanging fruit.

The article from which this sentence was taken out is about economics, and the word driver apparently refers to "a factor that has a material effect on the activity of another entity." (Driver definition in economics)

Thanks for your time

The money is metonymy for the investors, and low-hanging fruit is an idiom for

the obvious or easy things that can be most readily done or dealt with in achieving success or making progress toward an objective

"leaving the space" is not an idiom but an intelligible metaphor saying that investors are leaving this area of investment for others where profits are more easily made.