For example some loudspeakers have computer designed crossovers that take into account the dynamic and LRC parameters of the drivers. These designs are listener tweaked with multiple sets of electronics and cables. Others have 'cookbook' crossovers predicated only on the nominal driver R and receive minimal tweaking. Some of the these can be very good and achieve cult status simply because the designer got lucky.
OTOH, the engineered design could suffer from all manner of things beyond the engineers control: voice coil former, diaphragm, surround, capacitor, glue, gasket, laminate, etc. deterioration or a bad business model and simply fade away.
Some designs are so egregious as to be almost unlistenable but are still capable of resolving differences between preceding components and so, as they get better, the improvements are detected.
It is uncharitable to lay blame for one's inability to accurately predict the future