The whole software/startup approach is currently based on user growth which relies on retention, trigger, actions, and rewards. Long-term investments don’t fit that model so there is no incentive for them to encourage that form of user behaviour.
When the market gets more volatile or if there’s a sharp downturn, that would become a big issue. Not sure they had to address this yet because since 2014 their founding year the market had been on a smooth, upward trajectory. A recession however is already around the corner.