Wealthier people also receive much greater benefits from the government. The court system makes complex contracts possible in a way that really only benefits holders of capital. Infrastructure for transportation and information technology benefits everyone, but especially people who own companies that ship goods and deliver services over the internet. Government contracts benefit people who have a stake in the companies that service those contracts. The police tend to provide better protection to wealthier people in wealthier communities, who have more to lose from property crimes in any case.
In case you're not persuaded that people who can afford to pay more taxes should pay a greater share, all of these things are valid reasons for the wealthy to kick in a lot more of their wealth, in relative and absolute terms, than other people.
In case you're not persuaded that people who can afford to pay more taxes should pay a greater share, all of these things are valid reasons for the wealthy to kick in a lot more of their wealth, in relative and absolute terms, than other people.