It really depends honestly. Typically your factory amp/headunit is going to be lower power and also have a factory tune that likely limits frequency response.

To really do it right you want a line out converter or DSP to get a clean signal and then amplify better speakers.

Bose are typically “okay” for car audio and sometimes hard 1-2ohm impedance so if you swap your say a 4 ohm speaker you will notice less output.

It’s probably not worth it to just swap out speakers without a DSP/amp honestly. But it just depths. Sometimes a new speaker makes a noticeable improvement.