~/Documents/Adobe/Adobe Illustrator [Version]/AutoSave/
These files usually have the original name plus _recovered or a timestamp. Illustrator may also write temp files to: adobe illustrator recovery file location mac
~/Library/Application Support/Adobe/Adobe Illustrator [Version]/[Language]/Recovery/ adobe illustrator recovery file location mac
Same "Go to Folder" method – paste: ~/Documents/Adobe/Adobe Illustrator 27/AutoSave/ adobe illustrator recovery file location mac
If none of these work, the file may be permanently lost – but or a cloud backup (Dropbox, iCloud) is your final hope.
/private/tmp/ or /private/var/folders/