There's a big incentive for companies that need to hire more people to give the "better" title out for the same kind of work. If managers do maintain a gold/silver role on their team all of the folks in the silver role will look at the gold role as their next move. Worse there is a net-negative productivity drag where the gold/silver role constantly debate what's in-scope vs. out of scope for their work.
I once saw a team where the scientists were meant to be equivalent to SDEs in coding skill, but the scientists could only in practice do some light python/bash scripting. They tried to make the SDEs responsible for "productionalizing" the projects which meant adding tests/etc. The engineers who could all left the team in 6 months, the ones who remained were also unable to perform more than light bash scripting/python work.
Caveat is that many scientists are expected to publish novel research to advance their career. "Infrastructure" and "data management" do not tend to produce the kinds of sexy projects which are attractive to publish.