Similarweb shows a consistent ~15% YoY decline. It also shows growth beginning in early Summer, so this trend may be changing as of very recently.

Sensor Tower shows a consistent ~10% YoY decline.

DataReportal/Kepios shows a ~5.3% decline in ad reach.

EU DSA Transparency repoorts shows ~10% decline

Pew Research shows a >20% decline in the US.

Regardless, I still use X and find a lot of value from the people I follow. I'm paradoxically optimist.