The line spacing between bookmarks in the bookmarks panel is now a full line, meaning the content of this panel is 50% wasted space. Plus they are all indented, which is more wasted space especially because many now spill over onto a second line. On my 1440-pixel tall display, I can see 30 items. But if I open the same document in Firefox, the bookmark panel shows 42 items. So it's much easier to find what I am looking for in a long document.

Please don't design everything for touch. I don't need giant touch targets. I want to see more content. PDFs are about reading and finding information, and requiring more scrolling to get to everything is not helpful.

(I also don't like that you decided for no reason to move the bookmarks from the left side to the right side.)