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.