I think what stripped away the last vestiges of my libertarianism was seeing how private control of communication channels leads to people being deplatformed with zero rights, zero process, zero appeal, zero means of redress, etc. See, it turns out that the most economically efficient way to dispense justice is to simply crush the most troublesome 0.1% without any process whatsoever, and only seriously investigate anything if there's a substantial amount of money on the line.
What we see with the internet and banking is something that would happen with phones, electricity and plumbing if it weren't for public utilities laws written decades and decades ago. "Ah, this asshole said 'nigger' on an alt-right podcast, and now ABC and Now This and everyone are giving me shit about doing business with him? Fine, no more electricity, water, gasoline, or communication for him. Fuck him." Press the button, and now that guy is just not your problem.
Sure, he can't like...travel or have heat. But it's 1 customer out of millions, and it took 2 hours for the media to make it not worth it for you to keep his lights on, no matter how faithful he's been about paying his bills on time. And maybe it turns out latter that some redditor falsely identified him, but who gives a shit? Just one customer out of millions, it's not worth the time to even hear his appeal. This is the world libertarians want.