Deleted large amount of files (ca. 300GB) from MacBook Pro but the storage that is left remains the same

Deleted large amount of files (ca. 300GB) from MacBook Pro but the storage that is left remains the same. DaisyDisk shows about that much in "hidden space" (even with administrative privileges used to run the app). I wonder if the finder hasn't caught up with the deletion or whether something is cached from earlier. Having deleted that much from my drive I was expecting to free up the equivalent amount in space.

I'm sure this has been asked dozens of times in the past but I haven't seen an explanation. Thanks.