Sure. That's why Brazil fled to Bluesky instead of Threads when Twitter was blocked. It's probably successful among boomers and whoever already has another account with meta.
I'm not sure how that's entirely relevant. Success of another platform doesn't imply failure of another platform. It's also relatively common for different regions of the world to settle into different social media networks and messaging systems. See: Whatsapp vs iMessage, VKontakte, WeChat, telegram and so on.
There's plenty of metrics to support the fact that Threads is a successful launch.
More like 175M Threads users alone. They have already been set up for success given Meta's userbase. Now they have to herd that demographic among their different apps, so it was only logical to have a Twitter alternative in order to retain their usebase and profit from Elon's task oriented leadership that has materialized in Xwitter shedding users.
There's plenty of metrics to support the fact that Threads is a successful launch.