A better question would be what percent of the wealth do they own? That would be much, much higher. If your investment portfolio doubles, are you richer? Of course. But it doesn't count as income. You're just making money off the backs of the poor whose wages are being depressed in favor of giving more money to capital.
Disposable income would be a better metric in this case. They may earn only 24% of the income, but how much of that is excess? ie. beyond providing their needs.
For the other 76%, all of that income may be spent on just food/rent/other essentials. Whereas the 1% have excess that they can save, or spend on luxuries. That's why tiered tax regimes exist.
NB. The definition of "needs" is obviously very debatable. The top 1% in California is defined as ~$90k, but given a median rent of >$4000/mth in SF, that skews the needs/excess taxable money argument considerably.