That's exactly why, because the original OP fandom is no longer young, and the current new generation is also used to watching anime with better quality and that are somewhat more modern. You'll never convince a child today to watch more than a thousand episodes of an anime from several decades ago, and the same goes for young people and adults. That's why this remake is extremely necessary, not only in One Piece but also in many other great works of the action and fantasy genre such as DBZ, Bleach, or Naruto.

I've been waiting for years for that "remake" which is like four or five chapters, I don't remember exactly, of Naruto by Pierrot (if I'm not mistaken). I am really interested in seeing the Fourth Hokage thing, to be honest. But well, what I'd really like to see is a remake more like what Netflix has already done with other works like Ranma ½, for example.

All the best.