Despite how quickly trends/content can age on the internet, you shouldn't mistake that for actual transitions in platforms.

There's a ton of logistical and infrastructure-related issues that need to be sorted out, but you're being defeatist if you don't think that just because there haven't been mass migrations within a year, any sort of shift is irrelevant.

Twitter and reddit have incredible momentum and it takes a long time to slow them down.

Just look at how desperate Twitter has been with their advertising - I don't think anyone would say they haven't suffered some incredible damage over the last 8 months