In BG1, which actually took place in Baldur's Gate, you owned neither house nor stronghold.
In BG2, you were able to occupy or otherwise take over a stronghold, in SOME cases, in others you are simply promoted to a position of some authority (cleric and paladin for example). This generally required mid to high levels and class related quests.
In as much as BG3, at least so far, involves lower level, and quests entirely unrelated to ones class, as well as a more survival directed goal ( not becoming an Illithid) - I still fail to see how a stronghold or a house folds into the plot.
Pathfinder justified it as you were building a realm. PoE tried to justify it through the plot, as the major dungeon was beneath your stronghold. PoE2 gave you a boat because, pirates...
DA again justified it as you were building up what had once been a "class" stronghold as a defense - it was a somewhat central part of the plot
This seems to be one of those things somebody always feels necessary in RPG's these days - the itinerate adventurer seems to be a lost cause. I'm all for it in most games, where it is justified by the plat, but so far don't see a rationale for adding it to BG3 except that it would "be cool".
Not to mention the developmental time eaten up by creating mechanics to properly place all that collected junk around your house!!
In specific response to your final line there that I put in bold, there are no special mechanics needed. We already have the ability to not only drop and place items in our current camps where we want but we can rotate items with the mouse wheel to change around their position when placing them. Nothing more is currently needed except a static location in Baldur's Gate to use the same way we currently are able to use our camps.
