This is an extremely interesting debate.
Firstly, supply and demand dictates wages in Europe in the main, with some union nudging. The 1500hr rule was knee jerk in USA, causing the shortage which drove up wages.
Does does 1500hrs make someone a better pilot? Maybe.
Sometimes a candidate requires experience to grow themselves, mature their character, it’s not all just hand eye coordination, a lot of soft skills to learn. I see this a lot with new cadet firsts officers, lacking in people and communication skills, then you see a mature second career modular cadet pilot that has all these attributes from their previous career/life experience. Perhaps the 1500hrs flying will involve a few hundred banner towing being self sufficient, a few hundred instructional, giving briefings, learning how to honestly debrief students, a few hundred flying single pilot freight work, IFR at night etc etc, producing a well rounded candidate,
Also a huge portion of this is down to selection and training as well. For example the military, looks in-depth at personality traits and leadership potential, then has a highly regimented officer training followed by flight training which will see people on the front line in something very fast and pointy after about 400 (not 100% sure) or so hours.
The selection process in flight training schools, is basically can you pay for it (they pretend to do tests, I doubt anyone fails..) the training is then often taught by a few categories of instructors, new CPLs doing their first job passing through n bad habits they were taught a few months before, or instructors that have never passed an airline selection for various reasons and become career instructors (even if they are not suitable to teach...) or retired Air Force/airliner types often fairly ancient and with dated attitudes to teaching, or the rarest kind, someone that loves teaching and has or is currently an operational pilot for the love of it.
The training syllabus is then also ancient, teaching things as pointless as timed turns (when was the last time this was done in anger? WW2?) It needs dragging into the modern days, being relevant to the skills and techniques relevant to the class/type of operation the student will go into.
Then at some airlines the last selection process is just some maths tests, a “tell me a time when”type interview and go in the sim for a v1 cut and raw data ILS.
This is still leaves untested much of the soft traits that you can rarely see until it is too late on the line, sometimes during a non normal event.
The entire process is not fit, designed by ancient regulators out of touch with reality after being lobbied by airlines desperate for crews that want to lower standards and speed up the process.