We are digital librarians. Among us are represented the various reasons to keep data -- legal requirements, competitive requirements, uncertainty of permanence of cloud services, distaste for transmitting your data externally (e.g. government or corporate espionage), cultural and familial archivists, internet collapse preppers, and people who do it themselves so they're sure it's done right. Everyone has their reasons for curating the data they have decided to keep (either forever or For A Damn Long Time (tm) ). Along the way we have sought out like-minded individuals to exchange strategies, war stories, and cautionary tales of failures.
There are a lot of things you could try that would make it much more difficult for a competent data recovery specialist to recover your files.
If your gas furnace with a circuit board stopped working, would you take it apart, asking questions on Reddit about how to find it?
I have no relationship with www.myharddrivedied.com except as a happy customer (an SD card failed onsite before I could back up important photos).
Go with the experts.