"if you have any questions, please call myself" and other bizarre new reflexive pronoun usages

This is not a question about when to use reflexive pronouns. I am perfectly clear on that, and I understand that there are questions on the site already about when and when not to use them.

This is a question about what seems to be very sudden general confusion about reflexive pronouns.

This is something I see and hear (but especially hear) more and more in North America (I won't pretend I know what goes on linguistically in the street or on the tube (either meaning) in other parts of the world): the use of reflexive pronouns in place of subject or object pronouns, particularly for first and second person.

Examples:

If you have any questions or concerns, please call myself.

You can give it to either Dave or myself.

Okay, I'll give it to either Dave or yourself.

Hearing this drives my inner snoot batty.

So, why? Why have North Americans (and others, if this phenomenon is global) started doing this? I'd love to read any reasonable explanation that doesn't discuss why these examples are incorrect but somehow addresses the question of why this has suddenly become more common...

Myself too, drives I wild.

Joking aside, I've only ever come across the misused reflexive pronoun in a formal context. You would never overhear someone saying, at the end of a date, 'Call myself tomorrow, OK?' But I'm sure many of us have received emails containing sentences a little like this: 'In the event of any further questions going forward, please do not hesitate to contact myself.'

As suggested by others above, this could be done in order to sound more prestigious. 'Myself' sounds weightier, more formal than 'me'. And I think it's also a question of rhythm. The extra syllable affords a pleasing metre. On the other hand, 'me' sounds blunter and possibly more egotistical, more demanding. 'Contact me.' Not anybody else, not him or her: me.

And as we're taught, 'me me me' is bad and selfish; myself is perhaps a gentler creature.

The misuse of "myself" has been common in London (and therefore has spread across the UK) for more than 40 years. When I moved to London from the North of England, I was amazed at the poor standard of English even amongst professionals. It was sloppy, imprecise and often wrong. Notably, much of it was already in use by those in their 40s and 50s suggesting that the failures originated even earlier than I found them.