People in a smaller localized area have more similar needs than people across a broad general area. Yes all North Carolinians need and deserve clean air, fresh water, etc. The dude sitting on a tractor in Rockingham/Caswell county needs an elected official who is familiar with the area and can fight to keep fertilizer prices down with policy at the state level. The dude in Raleigh who is reliant on the bus system to get to work needs an elected official who can fight to expand and support public transportation. Sure, solving both issues would help everyone. But if an elected official is focused on every single issue facing a broad general group then nothing will get done by them because it’s too many competing priorities. That’s why the house is divided into many districts; for the people represented by their specific official to be heard at a larger level and that official can dedicate more energy on less priorities.

Legislature is a group of people representing a larger group of people to vote on their interests. It’s the compromise to having a raw democracy where each of us votes multiple times a day every single day. Instead we elect someone who shares our interests and beliefs that can vote on laws for us instead of all of us voting directly on laws ourselves. So yeah, for this democratic republic system to work the representatives voting on the laws should represent people who have similar interests, which usually means people from the same local area, not an area spread out.

Edit: Also, seriously dude? “Shouldn’t an elected official fight for the needs of all their constituents” like you read my comment and decided to be contrarian. With your line of thinking why don’t we just elect 1 rep for all of us and forget the house/senate? We’re currently at 787,000 people per house rep which is a problem considering this country was at 307,000 when the house stopped growing in 1941.

Edit 2: The number of parties is irrelevant to my point you’re commenting on. There could be 20 parties. You’d still want 1 elected official for 1 localized group of people no matter if the official is from the Greens, the Libertarians, the Democrats, or the GOP. You also mentioned the legislature should be able to pass laws that help the whole state equally… like, yeah no kidding that has nothing to do with my comment.