>Entities training models have no incentive to follow such metadata. If we accept the premise that "more input -> better models" then there's every reason to ignore non-legally-binding metadata requests.
Name two entities that were asked to stop using a given individuals' images that failed to stop using them after the stop request was issued.
>Robots.txt survived because the use of it to gatekeep valuable goodies was never widespread. Most sites want to be indexed, most URLs excluded by the robots file are not of interest to the search engine anyway, and use of robots to prevent crawling actually interesting pages is marginal.
Robots.txt survived because it was a "digital signpost" a "digital sign" -- sort of like the way you might put a "Private Property -- No Trespassing" sign in your yard.
Most moral/ethical/lawful people -- will obey that sign.
Some might not.
But the some that might not -- probably constitute about a 0.000001% minority of the population, whereas the majority that do -- probably constitute about 99.99999% of the population.
"Robots.txt" is a sign -- much like a road sign is.
People can obey them -- or they can ignore them -- but they can ignore them only at their own peril!
It's a sign which provides a hint for what the right thing to do in a certain set of circumstances -- which is what the Law is; which is what the majority of Laws are.
People can obey them -- or they can choose to ignore them -- but only at their own peril!
Most will choose to obey them. Most will choose to "take the hint", proverbially speaking!
A few might not -- but that doesn't mean the majority won't!
>If there was ever genuine uptake in using robots to gatekeep the really good stuff search engines would've stopped respecting it pretty much immediately - it isn't legally binding after all.
Again, name two entities that were asked to stop using a given individuals' images that failed to stop using them after the stop request was issued.