Its not the tax side, its the payout side. SS pay out based on income is much, much less as percentage of high income earners due to so called "bend points".For Medicare I think you're right but for Social Security I don't believe so since for 2025, the Social Security tax limit is $176,100. You don’t have to pay the Social Security payroll tax on the amount that exceeds that limit. Of course you could argue a big chunk of 176k is "high earners" but as far as I know there is no higher tax rate like Medicare has on higher earners.
Social security simplified using current rates. Currently - you and your employer pay 6.2% - up to 12.4% total - which is capped at 176,100 - or $14,675 per month.
The bend points based on AIME:
90% up to $1,226
32% from $1225 to $7,391,
15% from $7,391 to $14675 - after is capped.
So doing the math, someone who's 35 year AIME was $1226 per month, '
Monthly benefit $1103 / month - or 90% of their monthly earnings as a worker. They and their employer would have paid 12.6% of 1226 = $154 to get their $1103.
Someone that paid in the max for 35 years of $14675
Monthly benefit = $4018 - or 27% of their monthly earnings as a worker.
They and their employer would have paid in $1819.70 per month to get that amount
The system has always been set up for the highly paid worker to pay for the lower paid ones.