I'm not defending the terrible writing but by this point anyone reading Rebirth/VRMMO/Isekai should know that quality writing is rare as fck, people getting triggered by slavery and beta MCs should know that it's what sells and it won't change unless you're willing to read Mangua and Manwha and those are bad on their own traits.
Japan didn't have that much slavery culture and that explain why they don't demonize it as much as the rest of the world and since it's a easy way to get the plot moving in terms of companions it becomes an ideal trope for these genres where the MC is usually alone.
Look at any romance Manga the FL is always a childhood friend a classmate or a work colleague, they don't interact on sight with anyone outside of the regular social circle because that's way harder to write and move on, on a new world if you get isekaied alone then a quick way to force the plot is a slave otherwise you end up with "in another world with a smartphone" where the people around force the girls into Touya life.
Chinese writing goes like this "I'm the big shit now you're my woman" and Korean is a mix of both but they end up leaning on the pre-set "romantic interest" being introduced by others.
Nobles are a easy way to get a villain or a convenient ally without developing the character since others can dump the exposition and the MC won't get involved with it until it becomes a direct problem or a crime by omission scenario like this one appears.
Usually on these works we are supposed to put ourselves on the MC shoes to have a power trip and they won't go out of their way to change things since some people will get disconnected by that, neutral choices are what keep the MC relatable and some changes come with consequences that the average reader can't deal with.