The UI/UX design is not about standards and guidelines but about what the manager currently likes. There is no discipline because senior managers don't care until Excel cells turn red.

Steve Jobs was forcing design discipline across Apple products with furious determination because he actually cared.

That's how it ends, everything becomes an unmanageable, constantly changing mess because every manager likes something else and big firms are rotating their personnel every 3 years.

Because the above products of the same company are losing cohesion and consistency even if they are in the same product line which results in bad UX.

Design departments are not disciplined enough...