Well off pensioners will have long since made sound financial planning which will have factored the state pension into their revenue streams, and one considered a return on an entire working’s lifetime of NI contributions etc.
If you want people to take care of their own financial future and not rely on the state then by all means offer some alternative incentives, but letting people contribute for a lifetime and then suddenly introduce an arbitrary line based on asset wealth, home ownership or whatever criteria meets your political leanings is, whilst understandably very appealing to some, frankly ridiculous and political suicide.