That is because CK3 is only trying to model a single relatively narrow 'slice' of history both geographically and temporally compared to either Civ or HK, which 'model' history with a much broader brush, covering far more variety of cultures and a far broader time-scale.
One is ahistorical deeply, the others ahistorical broadly.
The recent games like CK3 and Old World show what can - and cannot - be done by going 'deep' into a single Era and area, just as EU in all of its permutations shows just how deep you can go with a single Era even when you try to extend it world-wide in geography.
CK3, OW, EU are all very good games and show what can be done on their strictly-defined platforms, but they also illustrate the difference between themselves and a wide-ranging 4X like Humankind or Civ: imagine trying to implement the family interactions of CK or OW or the myriad diplomatic factors of EU on a 6000 + year time scale: trying to combine 'deep' and 'broad' is trying to be All Things At Once, and therefore Nothing Done Well.
- and, IMHO, the balance in a broad 4X hasn't been adequately solved by anyone yet . . .
Ehh CK3's version of feudalism is rather shallow and presents it as a strict hierarchal structure when it was really a web of relationships and contracts. A king for example could be a vassal for a lower noble and of course only contribute what was required by the feudal contract between them.