The problem is waste of time, energy and resources for both applicants and employers. I am a recruiter myself and been working in HR for the past 10+ years and

The problem is waste of time, energy and resources for both applicants and employers. I am a recruiter myself and been working in HR for the past 10+ years and obtaining a reference is not as simple as you make it sound, which is a phone call away. There are many instances when ex employer quits a job, relocates, doesn't respond to phone calls, hence the new employer and applicant both waste time chasing someone who is not available to provide a reference. Saving paperbased references is a very old method of safe keeping references, noone these days carries a file of credentials when they go for interviews, hence, storing paperless references saves them the trouble and they can forward them to any potential employer. Similar for the employer its a simple system, no need to engage in multiple email exchanges or phone calls, simply use one simple platform, once the reference is done, save a pdf, or delete it.