Red states have always been low population states. Over time every state grows, but the big states were already big. The smaller states have more room to grow, big pop states are more expensive because of the population so grow less.
It’s not some conspiracy, it’s just math. Now the Senate is another thing. There shouldn’t be two Dakota’s for one thing, and New Mexico didn’t have the population to join either.
We could combine the Dakota’s, Montana and Idaho and almost have 1 state worth of population.