Accreditation is an assurance of high quality training that is recognized by the profession. For example, the Saskatchewan College of Psychologists requires PhD psychologists from non-accredited programs to do an extra year of supervised training before being registered.
Some employers of PhD psychologists may also require graduation from an accredited doctoral program, and it can benefit you in other ways:
Regulatory agencies often fast-track applicants with degrees from accredited programs. Accredited degree programs themselves primarily hire graduates from accredited programs.
Note: The Canadian Psychological Association does not accredit master’s degree programs, only doctoral programs.