Buyers Request was implemented as a means to help buyers find potential sellers to work on their project(s). It was never meant to be a permanent source for finding work. Obtaining clients is up to the seller and fiverr has provided many professional development resources over the years to assist with this (the Learning Center, Blog and past Podcasts).
If you do a search of the forums on how to get clients, you will get posts by seasoned professionals on how to go about putting your best foot forward to get the attention of potential clients. By seasoned professionals, I'm talking about the ones that leave meaningful responses, not suggestions of the likes of spamming social media and contacting buyers without permission.
The suggestion of creating a Buyers Request system like that of Upwork is a bad idea as it's based on a bidding system and may attract the wrong kind of buyers. There are some marketplaces I'm familiar with who have a Buyers Request equivalent, but it's restricted to a chosen few which I know some will complain if that style of Buyers Request gets implemented here. Fiverr is constantly changing, and many sellers are adapting to the ever-changing environment.