The permanent re-apportionment act was a compromise settled in 1929, it caps congressional seats at 435 among other things including the census.
The reason the apportionment act needs to be repealed is because the American people are not being represented as they should be. The cap on representatives has had the negative consequences of forcing voting districts to be sized by population with 750,000 individuals per district. Originally the progenitors of the constitution regularly advocated for voting district size to be capped at 30,000 people.
Repealing the reapportionment act and replacing it with policy that limits voting district size would do a few things in one brushstroke; first and foremost being lowering the barrier to entry for representatives. An individual would not need nearly as much capitol or name recognition to run for office, in fact it would provide for the opportunity for his/her constituents to know said candidate and communicate directly. Raising the number of Congress members would drastically reduce the number of bureaucrats within the government as well, simply by removing the middle men in the process of representing the American people; And finally another benefit and possibility the most compelling, is that small 30,000 people voting districts would not only stop Gerrymandering entirely it would make any attempt at doing so functionally impossible.