I think that it was less: let's find alternatives, than it was fuck you government TikTok isn't Chinese enough. It was a direct answer to the government telling us which social media apps we were allowed to use. Also, 100% avoidable if they'd passed data protection instead. It really felt like the government enforcing private interests on its citizens.
Americans typically don't like the government telling us what to do. It's all fine if Facebook buys all the competition, but it's another thing when the government makes the competition illegal because they won't sell to zuck or musk.
Honestly, Redbook was sort of neat. I doubt it has much staying power as it was really just a protest, but it was sort of a historical feeling moment.