Why would you choose old over new? Here is a head-to-head comparison.
The core engine of AnyDesk has always been its proprietary video codec, DeskRT. Version 5.4.2 featured an optimized version of this codec, specifically tuned for lower bandwidth environments. anydesk 5.4.2
The answer is
You could print a document from a remote PC to your local printer. This used the "AnyDesk Printer" virtual driver—stable and reliable in this version. Why would you choose old over new