There is no credit card that would give a HHonors Lifetime Diamond status. You do have a HHonors Lifetime Diamond when it is written in your HHonors account. Period.
Achieving HHonors Lifetime Diamond is much cheaper than Hyatt Lifetime Globalist. I would share the stays between Hilton and Hyatt putting preference to Hilton Lifetime Diamond qualification after 12-13 years. Then you have at least something for lifetime and not depending the credit card existence.