This would be true if it was a country that banned TikTok. But the US is very interconnected, people in Montana have friends etc in other states who post regula

This would be true if it was a country that banned TikTok. But the US is very interconnected, people in Montana have friends etc in other states who post regularly on TikTok, so they would be motivated to download APK's (or use a web version). They'll need a VPN too of course, but that's not particularly difficult. They've already heard NordVPN's ads on YouTube.