I disagree that the LaTeX pdf looks better than the LibreOffice pdf, because fully justified text is less legible. If you take your eyes off the text for a moment then it's harder to find your place again. It's all one featureless block with nothing to guide your eyes. The uneven right edge of the LibreOffice version makes it easy to distinguish individual lines. This is especially important if you're skim reading.
But I recognize that some readers prefer the fully justified version. This suggests that the real problem is designing for a fixed page layout. It would be better to publish in something like EPUB, where you can display it however you like. Everybody I know who reads scientific papers reads mostly on screens now, and I think this is common. The printed paper version is more for archival than actual reading, so it doesn't make sense to prioritize paper based typography.
But I recognize that some readers prefer the fully justified version. This suggests that the real problem is designing for a fixed page layout. It would be better to publish in something like EPUB, where you can display it however you like. Everybody I know who reads scientific papers reads mostly on screens now, and I think this is common. The printed paper version is more for archival than actual reading, so it doesn't make sense to prioritize paper based typography.