A sham? Unless you argue that most people are buying property under false pretenses, especially given the public nature of property taxes, the expectation would be that those purchasing land do so understanding the existence of on-going financial duties.

As to why land is potentially materially different from other assets:

1. Land is only yours while some party will coerce all other parties to respect your claim. The cost of that infrastructure is on-going.

2. Most land might accrue some small value because of the actions of the land owner, but mostly accrues in value because of externalities from the action of others. Taxing those externalities so that the commons benefits rather than the individual seems at least equally as just as the current model where the wealth generated by collective action is overwhelmingly privatized. Reasonable arguments can be made for deferring that tax until sale or equivalent, rather than on a continuous basis.

3. In terms of being inexorably linked to specific governments, land is much more akin to citizenship and / or residency than fungible widgets. Citizenship and residence also frequently incurs ongoing tax duties.

4. Other scarce asset classes have been controlled in the past: https://en.wikipedia.org/wiki/Executive_Order_6102

You're right, everyone knows it's a sham, that doesn't make it NOT a sham.

City infrastructure needs constant maintnence, city services need to be constantly funded. And local schools (where most property tax in much of the USA goes) keep going even after your house is built (suffice it to say, areas with the best schools have the highest property taxes).

> And why is the amount you need to pay pegged to what other people in the neighborhood around you are doing?

The more developed your property is, the more city services you consume. And this is ignoring the speculation deterrence that property tax enforces, which is very important also.