That's a very ignorant opinion. The underlying tech in the headphone jack is the analog audio signal. It's more than 100 years old but it's a fundamental one. All wireless headphones rely on it as well. In phones with 3.5mm jack, the signal amplifier is located in the phone. The analog signal gets sent to the headphones. With BT headphones, there is an extra step involved: the phone sends digital (BT) signal, this signal gets converted to the analog signal in the headphones (or a dongle), at which point it becomes the "100yr old tech", then it gets amplified and sent to the speaker(s). Inherently, BT can't improve the quality here. It can (and often does) make it worse though.
Is not it funny how people get blinded by Apple (or other company) PR and start paying extra bucks for worse quality? Sure, wireless offer convenience in some situations so it has its place but it's not a superior tech.