What are the advantages of selfies for security?

A former client of us hired us again after 3 years. In that period, they had many changes, one of them the use of selfies for security reasons.

I have found this type of security from time to time, and I was always interested in how it would help a security or UX process, and I could never find any conclusive information, but I could find many weaknesses.

Unfortunately, this use of selfies with my client is not negotiable. Although they cannot articulate the reason why this process is good, they spent a lot of money on the system and are not willing to put it aside. Moreover, they are not willing to allocate resources to investigate what the experience of users is when using such a system.

However, I would like to know exactly what the real advantages of such a system would be, since as I said, I could not find any (the system has no facial recognition, which would be a valid reason). If there were real documented advantages, we could look for different ways of including such a system in a more complete flow, but honestly we could not find anything for which I turn to your help.

In case it helps, this system is for an investment company (fintech). And for some reason, it's becoming common both in fintech and in my country (Argentina) where most banks and financial apps use this technology in some way or another

Edit:

Some links with examples of what I mean:

An extremely technical paper on Selfie Security Technology