Can I just replace the original speaker to Prius jbl speaker

Upper right corner there's a button, that'll allow you to edit that title, for the next 11 hours and 58 minutes, if I'm not mistaken.

 

Since you are using an aftermarket Pioneer headunit, get any quality door speaker and all will be well.

JBL equipment is meant to be used with factory JBL equipment. Trying to mix components is not a good idea. JBL sepakers in a non-JBL system will likely sound bad and will likely die an early death.

 

The Pioneer headunit has more power than the weak non-JBL factory head unit. That is why the factory speakers sound better w/ the Pioneer.

Upgrading the speakers even w/ the factory head unit would have had the biggest impact.

Speakers come at various price points and have different sound characteristics. You will be happy with whatever you choose b/c it will be a huge improvement over the factory speakers. Avoid speakers that have a paper or foam surround; won't last as long as a speaker w/ a rubber surround. Stick w/ the bigger name brands that have been around. You would be happy w/ any of these:

Infinity, Rockford Fosgate, Alpine, Kenwood, Kicker, Polk Audio, Pioneer, Sony, JBL, Polk Audio, JL Audio, JVC, MTX​

If you add a subwoofer and a multichannel amp (ideally 5channel: 4door speakers + 1 subwoofer), you will definetly want to run new and thicker speaker wire to each door. This set-up would give you the best sound. However, if you want to spend as little as possible, you could have the head unit power the doors, using the factory wiring harness, and get a separate subwoofer that is powered or an amp + subwoofer.

You should search "how to upgrade audio systems" or similar words to learn more.
Read these sites as a start:
A 5-step plan for upgrading your car stereo system
How to Build the Ideal Car Stereo System | Car Bibles
Upgrading Your Car Audio System by Replacing Stock Speakers | MTX Audio - Serious About Sound®