In fairness, Warband was still very much a mom & pop operation, so the jankiness of M&B Original and M&B Warband was forgivable.
That said, Taleworlds never finished Warband. To this day, the game is full of half-formed ideas and bad optimization. That is the case with M&B Original, that is the case with M&B Warband, that is the case with M&B WFaS. Since very early in the dev cycle, most of the real progress in the M&B community has been made not by Taleworlds, but by the modding community. The most polished and complete "official" game - Viking Conquest - was actually created not by Taleworlds, but by one of the modding teams.
Taleworlds has a lot more employees now, but that hasn't stopped Bannerlord from achieving a "dev hell" reputation somewhat akin to Duke Nukem Forever. Many of the most glaring issues are things which have yet to be addressed officially, but were alleviated by mods made available within the first couple of days (see, for example, the popularity of mods like BannerlordTweaks). Given that the Warband era was plagued with problems that never got resolved, and now after many years of progress the Bannerlord era has shown no significant signs of change, I think it's fair to say that we need to temper our expectations and just accept that we're never going to get what we want from an official release. Bannerlord has a lot of potential, but the modding community will find it, not the devs.
-edit- I think of M&B like Minecraft. The basic idea of the game is brilliant. The devs hit conceptual gold! The actual implementation of those ideas...? Ehhh... that's a task for someone else.
It's the IKEA approach to game development; they provide the framework, but we need to build it ourselves.