I don’t think CCP has published player distribution since CCP Quant left but the last chart he gave us showed 75% of active characters in highsec and that number had been stable for years. It probably hasn’t changed much since.
Different regions of space with different rules give the game some texture - we need more variation, not less.
Niarja falling to the Triglavians makes trade between Jita and Amarr more difficult but not impossible. Even if the Bei - Colelie gate shuts down (Eclipse trailer) jump freighters can make the trip - and will if the price is right.
People will need to climb out of their nice comfortable ruts but change brings opportunity. Those who can adapt will prosper.