Banks have been doing this for decades. If you're not a VP within 3 months some may wonder if something is wrong with you.
That probably accounts for some of the VP titles. I kinda doubt that all the VPs in your average BofA office are always signing things, and couldn't possibly just go to their boss for a signature, like normal people do.
Every now and again someone whose spent a career exclusively in finance gets bitten by this when transitioning into the business world. A friend once told me a story about a deal with Amazon nearly getting tanked when I coworker chewed out an Amazon VP, saying they wanted to "talk to someone who could make decisions". Took a lot of massaging to salvage that deal.
edit: added quotation marks to just. I like being an IC.
Banks aren't trying to stiff their traders out of overtime. They do it because a VP has certain signing power as an executive that regular employees don't.
have been through this many times and very HR department on the sell and buy side says the same thing.