The shirts exists for one reason:
To put money in the pockets of John Inzer.
He's the man who started out all the shit in the late 80's. Originally, the shirts were made to support the shoulders, preventing injuries.
For many years, into the 21st century, this clown had a monopoly on benchpress shirts with the major organisation, the IPF. Meaning he could put out the notoriously shitty EHPHD shirt, who would break at the first lift for many lifters.
Then finally, Titan was allowed in, as well as Metal, and now we at least have durable shirts.
In several of the more lenient feds, different brands have been allowed for many years, but the major ones have been stuck with the fcuking Inzer until a few years ago.
There is going to be a throwback in the IPF in a year, with shirts having more stretch. Either you will never see a new world record in the IPF, or you will see new weight classes.
My guess is the latter, and removal of quite a few of the lighter classes, emulating the weightlifting in some ways.
-Hedge