Friendly reminder: Deleting your account won't accomplish what you think it will.
Facebook will still keep all data that is associated with other users as per their own disclaimer. They also still keep logs that are "disassociated with personal identifiers. "
So all training can still occur. And understand what while Jane Smith may have deleted her account, they still have all the data it takes to indicate that User 12345 was tagged in photos with John Smith at the Burger King on 404 Fake St. And, because of that, the data that User 12345 had previously provided is ALSO John Smith's data. And Fred Wilkerson since he was at that Burger King once. And so forth.
And ALL that data is still there for training.
So do what you gotta do to make it less appealing to other users. But understand your data is already out there and is never going away. Same with reddit and all other social media (which includes Lemmy).