My understanding of European feudalism (which is sparse, and comes from
https://www.amazon.com/dp/B00XTAXZAU/ ) is that it is characterized by the following features:
- The owner of land owns it outright. If you own land, you don't pay taxes on it to anyone. It's yours.
- Ownership of land is inalienable. Your land is yours, and you can't sell it or otherwise transfer ownership (except through inheritance).
- Land generates revenue through the collection of dues from peasants who would like to work it.
- The feudal dues associated with a stretch of land are fixed by tradition and, like the ownership of the land, can't be changed. This is why European peasant reform movements emphasized stable measurement units so heavily -- since lords couldn't change the nominal amount of feudal dues, changes were actually implemented by messing with the size of the units those dues were measured in.
- The king has no tax authority. He gets his revenue from the land he owns, just like every other noble does.
It is a radically decentralized system, even for the rest of the world at the time, and it reflects the very low level of societal development in feudal Europe.
The US property tax system is nothing like this. The government owns ALL the land, and no one else can ever own any. The government has tax authority over the land and many other things.
The proposition 13 system does look like it's trying to move things in the direction of feudalism, as far as I can see. It's even trying to make sure land can't be sold, in that when you sell your land, all the tax benefits are lost.