Yeah, every zone should have an equal number of horde and alliance players distributed equally throughout the zone with an equivalent level of gear and playing ability. Join a PVP guild or reroll on a pve server if you regret being flagged all the time.
That’s what I assume you’re looking to achieve with faction balance in a hyperbolic sense. It’s a bit of a fantasy. Everyone knew this was going to happen.
Most folks want to feel good by facerolling in pvp. You can have equal numbers of both factions on a realm, but most folks won’t bother to engage unless they can have “fun” by winning easily.
The population division has gotten increasingly worse. When I initially joined it was one of the more even servers. Xfers have allowed it to get very horde favored.