Ranking systems almost never expose the "knobs" to users.
There are a number of reasons for this.
First, there's the tyranny of the marginal user–if only 1% of users would have twiddled the knobs, then they're not worth building because it might distract and annoy everyone else.
Second, they lock in whatever ranking ontology happens to be used right now.
That makes it harder to change internal ranking signals in ways that don't fit within that exposed ontology.
Ranking systems often have fluid experimentation throughout all components that are hard to fit in a user-facing ontology.
If you change the ontology, how do you migrate users' previous settings?
Third, you might reasonably think, "the user might set things now based on current low quality in some sub-domain, but if we improve that sub-domain, the user might have inadvertently boxed themselves out of a better experience."
Fourth, exposing too many knobs might give insight into internal signals, making them easier for creators to game.
But finally and most importantly, consumer systems have an emergent gravitational pull towards engagement maxing.
A ranking system would never ship a toggle to "make me more bored."
This is probably the logic behind OpenAI refusing to make the memory feature user controllable.
Also, they think they can get away with it without too much uproar…
… and they're probably right.