stop saying. Open a PDF in LibreOffice Draw? Then your PDF will look completely different. This is not a suitable option at all unless you really have a lot of time to spare.
I’m the third in this thread of four comments to regularly use LibreOffice Draw to modify a PDF. I notice that layout a little changes, but this is limited to margins around pages and replacing fonts that you haven’t installed. The dismissive panic in your response does not deserve an “informational +2”. Someone once taught me that you can even import PDFs into LibreOffice Draw, and I found that suggestion to be useful and informative.
Nor can it be compared at all to the very simple and accessible Firefox editor. Yes, you could do a lot less than that, but at least it won’t change the layout or appearance of your PDF.
You can not adjustment made, but on its own comment. Therefore, they are in fact nothing editor. At most, a very basic layer is glued to your PDF.
If I want more functionality, I use Xournal++ instead of LibreOffice Draw.
I just tried it, but it seems you can also do it on your own with Xournal++ comment. Maybe I miss something?