Er, aren’t you disproving your own point there?

There’s two ways GIF can be pronounced, so we use both.

Beats having to say “Graphical Interchange Format” or spelling it out every time we want to communicate with someone.

The goal is to condense meaning as much as possible without losing the original context.

Although with some acronyms, it actually takes longer to pronounce the acronym than spell it out, and we still pronounce it because of vocal flow (easier for the mouth to string those shapes together).