I don't think an instrument or gear makes a player technically better.
I do think a more expensive instrument could be engineered to a higher degree and that could make it easier to play (example better access to higher frets, lighter, well balanced instrument vs neck diving, etc). I do think a more expensive instrument could sound better (proprietary or top shelf electronics, proprietary or top shelf hardware). I do think a more expensive instrument could look better (have you seen Canadian Dingwall finishes the past few years?). I do think a more expensive instrument could inspire a player to play and practice more.
I wrote could in every sentence above. There are expensive duds out there and other players may be totally satisfied with less expensive instruments. It's all good, for me though I stopped having a ton of gas after I got the expensive basses that I wanted AND they also sound/play great for me. It only took me a decade of trying out and flipping a ridiculous amount of gear to get here though