Apart from various "trust and safety" censorship and moderation activities, what new features or updates has Twitter done in the past 3 years? I can't think of many changes they've made beyond those things, except for adverse ones (like breaking Firefox compatibility for months).
Is it a conscious choice for them to actively do nothing?
MySpace died because it didn't innovate and refused to invest in the core platform. While Facebook was spiking in popularity, MySpace was still a slow ad-plastered mess. Twitter seems to be that sleepy giant who has stopped all progress.