Panose: is there a purpose for it nowadays?

John Hudson said:

Historically, it was devised to enable font substitution in printers, which is no longer an issue.

And another question is how a modern software/hardware used Panose numbers.
As I understand it, there are two likely reasons to add it to the fonts:

1. To support some old printers (and it doesn't make much sense today).
2. For possible use of these numbers in a future, in case a new useful application for this technology is found.

Erwin Denissen said:

Over the past two decades, users of our font editor have discussed Panose at our forum, and they even came up with a diagram

Yes, these visual examples are exactly what the documentation should have included. It's better to see once than read a hundred times.