Want to reduce paper by removing e=xtraneous crap on a PDF, tough crap says adobe. Remove picture, still half a lage hole I cannot remove or or reduce, want weird uneditable bars that pop out and no way to remove, we have that for you! Clean up formatting and make a 2 page bunch of poop a nice single page, easy to read document, hell naw, you go buy expensive software for that. Adobe does none of it. Glad I dropped 100+ dollars on DC to zip, zilch, zero of what I want. You bet your ass I won't again!
Edit and convert PDFs
Print and prepress
Sorry but while I do feel your pain, I also (apparently) have a better understanding the overall mechanics and structure of the PDF. The fact that we can do ANY of this editing in a PDF is truly remarkable. I've been working with PDFs since the very beginning and what we can do now is truly amazing.
You have to understand that Acrobat is not a page editor program. It's primary focus is to distribute digital copies of media to a wide variety of platforms containing a wide discrepancy of page sizes, fonts, etc.
If you really really really want to edit the content of a page to the degree that you want, you'll have to go to the original page creation program that made it. If you want to change a word here or there, you can do that with Acrobat.
However, here's one big tip: PDF pages made from websites: Go to a website called "Print Friendly" and do what you have to do to get the Print Friendly link integrated into your browser. Now, when you see a web page you want to make a PDF out of, without leaving the page, select the Print Friendly link. Now you will see your web page with more of a focus on layout and you can click on an add and delete it. You can click on any of the content and delete it. Then when you print or PDF the page, you will NOT have any empty spaces. The one negative I've seen with this is that sometimes (seldom in fact), it will remove images that you may want even before you get achance to decide if you want them or not. Despite that, this is pretty cool.
But again, Acrobat can no more do that than your car can fly and we've been promised flying cars for what, over 50-60 years?