Long captions cause the whole image to take up more space.
Even if the image itself is small enough to be wrapped, a long caption makes it impossible to wrap around.
Ideally, the captions would be wrapped to fit the image
Example:
#import "@preview/wrap-it:0.1.0": wrap-content
#let fig = figure(
rect(fill: teal, radius: 0.5em, width: 8em),
caption: [A really really really long caption for a fairly small figure],
)
#let body = lorem(100)
#wrap-content(fig, body)
results in

Long captions cause the whole image to take up more space.
Even if the image itself is small enough to be wrapped, a long caption makes it impossible to wrap around.
Ideally, the captions would be wrapped to fit the image
Example:
results in