I better example is probably Saudi, since it's an absolute monarchy and Oil Income is directly predicated on Land Ownership, which is owned directly by the monarchy or via a few feudal families, even if they are technically companies for the purposes of trade with capitalists.

Yeah. I’d just add that position differs from mode of production.

Crudely speaking, Feudalism is a mode of production characterised by the bonding of workers to the land, and the extracting of surplus value occurring via an in-kind tax. The political structure that facilitated this was one based around hierarchy of land ownership.

Capitalism saw that mode eroded, with the people involved in maintaining it either marginalised, or transformed into capitalists. Peasants were booted off the land and proletarianised.

Chattel slavery was formally abolished in the USA, but we still have echoes of the positions enforced by that mode of production. The children of slave owners are doing alright, and the children of slaves are, on the whole, not.

The same process can occur in socialist transformation, and was the rationale behind united fronts. A national bourgeoisie, subject to leadership of the proletariat, retains some of its status and privilege. The intelligentsia that managed capitalist production ends up managing socialist production as well. (Of course, this is conditional on actually supporting the new mode.)

We even see it occur in reverse. The socialist managers of the USSR became the capitalists when it disintegrated.