I don't think you have.
My point is: if accumulating a private pension results in your State Pension being taken away, what is the incentive to save? You have addressed points around that but not the the the fundamental problem I am raising. Your way means that someone could spend decades building a substantial pension pot, only to find that much of the income it generates simply replaces State Pension income they would have received if they not saved. Tapering it doesn't remove that problem; it just changes the rate at which it happens.
Your point 4 makes the contradiction even more obvious. You want to force people to save substantially more into private pensions, while point 1 proposes taking away their State Pension if they successfully accumulate enough. Compulsion might make people save the required minimum, but why would you then create a massive disincentive to save anything more? Surely we actually want as many people as possible building substantial private pensions. The more people provide for themselves, the less dependent they are on the state and the more taxable retirement income they have. Penalising people for saving beyond the minimum is completely counterproductive.
Nor does saying “the State Pension is a benefit” answer my point. It is a contribution-based benefit. Entitlement is built through your NI record. There may not be a personal pot with your name on it, but people have spent decades contributing under a system in which those contributions build an right to a State Pension.
I also made point about the wider social contract. If you continually tell people to work, contribute and provide for themselves, but then treat the fact that they did so as justification for removing things they contributed towards, you absolutely do undermine the incentive to do any of it. So no, I don't think you've addressed my counterargument. You have effectively explained why you think it ok to break the social contact to ensure whoever you have decided are the wealthy pensioners don't receive the State Pension. That's a different argument.
"The State in organising security should not stifle incentive, opportunity, responsibility; in establishing a national minimum, it should leave room and encouragement for voluntary action by each individual to provide more than that minimum for himself and his family."
William Beveridge - the father of the welfare state