How to make available space free
iMac 2017, intel i5, Monterrey 12.3.1
I deleted a metric ton of files (well, to be honest, only 75 GB), and while available space shot up nicely, by the amount of stuff I deleted, free space did not (I only got 10 GB out of it). How do I make available space free? Should I try to defragment the drive? Is there a guide for this kind of stuff I just missed? Everything I found on apple support tells me to delete files, but it's not really working.
iMac 27″ 5K, macOS 12.3