The cartridge is---as is the loudspeaker---a transducer. Both are the most variable (in terms of sonic character, color---the reproduction of vocal and instrumental timbre, and transparency) component in a system. IMO.
Likewise, the biggest contributor to the sound of a recording are the microphones, which are also transducers. Substituting a different recording mic can drastically change the sound of an acoustic instrument, far more so than changing any piece of electronic gear.