They killed those who opposed them swiftly, and have continued to do so. They took power through swift application of force.
No they didn’t. Most Afghani people laid down their weapons and didn’t oppose them when the Americans left. They stormed through the country so quickly because there was almost no resistance - in no small part because they were against Bacha Bazi and vowed to stop the practice.
I agree that it’s incredibly unlikely that the Taliban can be changed. However, I wasn’t particularly referring to social change via democracy. Either way, it’s up to the Afghani people to sort it out.
There was fairly widespread support (not unanimous) for the changes the US brought