I agree that it's more possible now to switch/choose alignment than it ever was. And being 'more possible' means that it must be happening more.

But "why people choose the communities they align with" doesn't seem much different than "why people have their opinions." Are we carefully choosing who we align ourselves with, any more than we're choosing our opinions?

I don't think there's any test for this, or any cure, other than making time to ruminate, meditate, and ponder. Alone. Free from distractions and other voices.

And if that's the case, isn't it at least possible that today it's both easier to switch communities, and less likely to be for any principled reason?