a new company tax computation

Nowadays we can keep record of nearly everything.

Of course we can keep record of shareholders and tax them, instead to tax the companies with a flat rate.

Then the profits would be taxed according total income of the individuals and paid by the companies proportionally.

Wouldn't this be a fair company tax?

ex.
we have 2 companies A & B with 2 shareholders x & y
x has 50% of company A and y has the other 50%
but x has 100% of company B

Nowadays we tax A & B with the same rate of say 30% but with the new computation this varies according total income of x & y, so x will pay more than y.