One can be a VP of 0 people.

Look into what the title means at banks!

I was an Executive Director / Vice President at Goldman with 0 reports.

Banks are the inversion where a Director is higher than a VP! An ED w/o reports is actually moderately impressive though!

Well, I was on the tech side which (at least at Goldman) has comparatively higher powered titles at less reports compared to the real bankers.

I suspect it's because the tech side doesn't run the model where ambitious young people without a clear idea of what to do go work for an investment bank for three years as sort-of 'finishing school'. So there are less juniors to herd for the techies.