When 100k people move in and you need a new water treatment plant. Those 100k people should pay for the water treatment plant not everyone that lives in the area who also paid for the last water treatment plant.

Further, you need to start building infrastructure now, not in 20 years when the new people have paid enough in taxes to pay for it. It's not like you need a new police station and a new school from a single new home but you do need them after X new homes.

Debt seems like the obvious solution to time shifting infrastructure, but that increases costs, adds risks, and still forces everyone to pay for new infrastructure. When a tiny home is worth 3x what would be somewhere else that value is from the existing infrastructure not the cost of building the house so adding a tax to capture that surplus is completely reasonable.