Isn't this, in a way, withholding information? I have a slight distaste in encouraging people to be ignorant, indirectly or not. Even if it's under the assumption that people who use these information take them at face value.
I do understand your concern, but they can be mitigated, IMHO by simply, in bold letters, THESE FIGURES ARE FOR ROUGH REFERENCE ONLY AND HAVE A VERY HIGH CHANCE OF BEING INACCURATE. PROCEED WITH CAUTION.
We certainly don't know the actual figures, but we do have ballparks. As long as it's taken with caution I don't see much harm.
I can only say this from nearly a decade of experience in interfacing with your average pedestrian individual who is interested in these matters... but yes I think encouraging people to accept that they are ignorant and thus they know that they are not equipped to be able to engage in certain discussions is important, until they can demonstrate the competency to wield it with context.
To be clear, there are some (emphasis on
some) ballpark numbers that exist. But that doesn't mean it should be open information and easily accessible -- not because we want to gatekeep knowledge, but rather because if everyone can access it, then it means everyone can use it in discussions without actually knowing the context and relevance for when to reference them.
If everyone were able to read and learn without actually posting things until they developed a minimum level of competency, then I would certainly have a different approach.
Putting it another way, it isn't so much that I think gatekeeping knowledge is the goal, but rather gatekeeping people's ability have discussions about topics that is kind of outside of their grasp and that when they post it ends up
creating more misinformation and more work for the rest of us in pursuit of accuracy.
Edit: alternatively, the idea of creating a reference sheet or site also by extension means that whoever does so needs to be sufficiently knowledgeable, respected and have good enough reasoning to be trusted to begin with ("subject-to-change" notwithstanding), which I don't think anyone in the community wants to yet claim that mantle.