When I was considering whether to try to make one happen the main reason was that users would need to treat it like learning a new language. That makes it rather high barriers and high payoff.
The other thing was that it would be murky whether “lets just gather more data / user activity” is done enough or will never get to a critical point. Narrowness makes it so that it actually gets used but makes it less exciting as a thing to have.
When I was considering whether to try to make one happen the main reason was that users would need to treat it like learning a new language. That makes it rather high barriers and high payoff.
The other thing was that it would be murky whether “lets just gather more data / user activity” is done enough or will never get to a critical point. Narrowness makes it so that it actually gets used but makes it less exciting as a thing to have.