Whenever you deleted a file, you just remove the entry instead of the file itself. First, the space of this deleted file will be marked as "available" for writing new data. That's the key point why you can apply tool to trace the deep entry and eventually find the raw files!
Accordingly, once new data occupies the marked area for "available", it's getting hard for any piece of software on the market to retrieve replaced and overwritten files. That's it. The sooner you find data recovery solutions, the more deleted files you can get back.
In here, I recommend [https://www.minitool.com/data-recovery-software/free-for-mac.html|MiniTool Mac data recovery] for your case.Which can hopefully recover deleted files from an emptied trash bin, a formatted hard disk, a crashed operating system and even a virus-infected Apple computer.
Hope that helps.