@jumia ….
Why do more powerful amplifiers impact speaker sound quality in a favorable way?
They don’t. Not always anyway. Several things should be considered. In example:
1. Amplifier power rating vs. speaker sensitivity
2. How does an amplifier handle impedance dips that some speakers present as a challenge to the amplifier. Some speakers with nominal 4ohm impedance may dip below 2ohms and not all amplifiers can or will handle it gracefully.
3. The size of a listening room and listening levels preference
Quality vs. quantity of watts and a proper matching based on the speakers you’re driving and size of your room are the most important considerations.
Just like with anything in this hobby, synergy is key.