They can, however, they require a certain understanding. I believe the perception on “nobility” is inherently terrible and ruined by low-fantasy roleplayers who know very little about how historical nobility functioned and just want a pseudo-GoT/pseudo-Mount&Blade RP platform. This is only exaggerated by the sheer lack of capability to portray powerful/influential characters.
There’s two sides to “fixing the issue”; there’s the “systems side” and the “attitude side”.
For the technicalities
I’ve roleplayed on platfroms before where a “system” regulated nobility and defined their influence through a shared DM. Heck, for 8 months I was a DM & loremaster like this in a community.
With appropriate “management”, noble houses can actually turn from cringe to a driver in roleplay where they seek to “outdo” each other in RP, driven to seal alliances, recruit and push their activity to its limits.
This management is, however, mostly frowned upon in the WoW RP community; it is largely incompatible with the general Laissez-faire attitude people tend to have
It would require noble roleplayers to sit down, form a community, elect a “management” and put limits on their claims/power. EG; define that there may only ever be three dukes and five counts amongst them - a community of 15+ families - always those who in-character earn it & rise to it, then commit the roleplay and resources to maintain the title. In exchange, the community agrees to recognise each others’ powers and titles, thus lending some base validity to their roleplay. Especially so when it’s not a whole bunch of lords and ladies claiming rule over wast swaths of land, but a majority of barons and baronesses with but a tower and a village.
In short, bundle up as a community to eliminate “high title” claims and “big power roleplay”. Instead, form a system to permit only a small portion of nobles to have that and make the rest have weaker / less prominent titles.
For the attitude
A core issue with “noble house roleplay” is the misconception that World of Warcraft portrays a medieval world. It’s a pill to swallow for many NORFARPEE people, but all manners of organization in the factions, all quests, all warfare and all hints point towards an early-modern-ish setting, especially when it comes to politics.
I don’t think we ever had much trouble with Nightborne nobility, mostly because the frivolous medieval stuff simply isn’t possible / feasible in lore as a Nightborne. You can’t make wild claims, your title is restricted by default to be titular and most like to follow the in-lore Iltheux - Astavar guidance where the Highborne are hinted to own a great deal of wealth & property in Suramar.
Everyone is sort-of equal there, and instead of making up frivolous lands and holdings, I’ve mostly seen Nightborne families try to place their characters in the field of business and influence. More wealthy socialites from 19th century Paris than the gritty Normans of the NORF.
Unfortunately, I don’t believe this attitude can shift or change. The general audience of house roleplay tends to be low fantasy roleplayers, at least amongst humans.
In short, what to do to make “House RP” viable
Unionise as a community. Bundle a dozen or more house guilds together and agree on cross-recognition and co-operation OOCly in exchange for maintained standards and possibly a system to prevent /anyone/ from laying /any/ claim, relegating people to rise in the ranks through IC intrigue instead.
Naturally, the above works perfectly well with the previously mentioned “fallen noble reclaims land” archetype as well.
If done well, in time you might build a name and be able to act in such a way.