Since you’re the one in disbelief, show us that it’s not true.
I have the right to believe that speakers have not improved unless proven otherwise. Speakers do not improve by themselves without human intervention. There is no proof required to understand that. Its obviously true.
Speaker designers aspire to improve the sound quality over time. Most audiophiles like you believe this is happening. Proof that this is really happening is required. That is the difference you dont seem to understand.
I have set you a challenge. You cannot turn the tables on me. You either give up or you give me proof. This is non negotiable.
There are two parts to the challenge. You would need to show that
1.there is a measurement that has improved over the years
2. that this measurement proves that sound quality has improved.