True enough. It seems weird since SMB has been in continuous use from about 1990-1992 until today (24-26 years), but CIFS was only in use from about 1996 to 20

True enough. It seems weird since SMB has been in continuous use from about 1990-1992 until today (24-26 years), but CIFS was only in use from about 1996 to 2000, so about 4 years of CIFS and 22 years of SMB, or about 15% of SMB's lifetime. Whereas SSL was in use from 1995 to 2014/2015, almost a full 20 years, and about 95% of SSL/TLS's lifetime. So it's obvious why SSL is still used during the transition, but less so why CIFS, which was just small blip in SMB's history, is used.