You can right click on a page and it's got "rotate" buttons up at the top. But when you click on one, it takes a second to think about it and then opens a popup to offer you a free 7-day trial of the Pro version. Rotating a page is too powerful a feature for Adobe to not try and sell it to you.
What you can do is "Rotate View Clockwise" three times, way down at the bottom of the menu. It applies to the entire document instead of a single page, and it doesn't persist next time you open the file. Works in a pinch but it's deliberately shitty.
Microsoft even had their own PDF viewing software with Windows 8, but instead of improving it to get their user experience one step closer to Apple's, they killed it off to make more people launch Edge by accident.
I can only assume there's a KPI somewhere in Microsoft HQ tracking how many times Edge is launched, and making that graph go up and to the right has become their number one corporate priority.
It would explain the taskbar's search screen, the "news and weather" bullshit, pressing F1 in Explorer opening a Bing search for "How to get help in Windows" instead of just giving you help, and most every other design choice they've made in the last couple of years.