> Who is "everybody" in this scenario?
Everyone that comprises the tax base that pays for the relevant infrastructure. In this case, state and local government.
> A single family dwelling creates a different impact than an apartment building. It requires different sewers, road frontage and utilities. Its cost is different. What you are proposing encourages expensive development.
On a per tax unit basis, apartments create much lower infrastructure cost that single family homes. An condo building with 100 units requires more sewer and road infrastructure than a single family home. But it’s got 100x the number of taxable units, and requires far less than 100x the infrastructure of a single family home.
> If a person pays the same whether they build high density housing or a McMansion, what motivation is there to actually solve the housing problem?
There is a natural incentive to build high density units in response to rising real estate prices, because you can make much more revenue per unit land. The market, unsurprisingly, provides the right incentives.
> If residents can't veto development, and communities can't put limits on it, you're left with very few tools to actually resolve important issues like urban sprawl that got us into this mess in the first place.
Urban sprawl was caused by existing residents legally requiring sprawl. For example, in my county, it’s illegal to build a house in most areas on less than 1/3 of an acre. I live in a pre-zoning law neighborhood where the lots are 1/5 that size. Even with the variances grandfathered in, a local developer had to fight for years to build three new houses conforming to the existing lot plan.
> Additionally, I would argue that's not how taxes work at all. There are many "use" based taxes: utilities, sales tax, special assessments, gas tax, toll roads, and so on.
Having a use-based tax that everyone pays is quite different than forcing new residents to foot the entire bill for shared infrastructure.
> EDIT: Additionally, when you say "proportionate share", I think many would argue that's what charging developers and new residents for new infrastructure is. They benefit from the new infrastructure, thus they pay for it.
Those people would be wrong. For example, people in my dense pre-zoning neighborhood pay our “proportionate share” for shared sewer mains and county roads. But 50 houses in my neighborhood pay about the same in taxes as 50 houses in a less dense area, but it cost the county way less to build sewer and road infrastructure to our 50 houses than to 50 houses in a less dense area.
For better or worse, our tax system is not built on paying proportionate to use. If it were, your point might be valid, but as I said, then new residents would get to avoid paying for a lot of other things they never used. If you charged new residents for the new infrastructure they require, then it’s not fair to make them pay for teachers and other public employees that retired before the new residents moved there. I’d take that deal in a heartbeat.