I am the only one who preferred the Warband companions (with a personality, that you could level up in a way you wanted) to the Bannerlord ones (randomly generated, generic, already leveled up)?
I don't have strong feelings about companions no longer having pre-written personalities, but the fact that they have lost all functionality except for leading warbands is a major issue.
The companions in Warband were useful as doctors, scouts, engineers, trainers, etc. They provided important skills that the party needed so the player could focus on leadership and combat.
However in Bannerlord, even if you find a companion who is a skilled doctor or whatever, their skill adds virtually nothing to the party. If the player isn't skilled in medicine or whatever then you just have to do without it.
Ideally they should've kept the system from Warband and then added the ability for companions to lead parties on top of it. So you'd be able to spec companions either as captains who are better at combat and leading troops, or as retainers who provide some kind of ancillary service to your party.