Why is there so little communication/cross-over between Adobe products?

The range of software and services provided by Adobe is indeed complex.  

A person with a deep knowledge of Adobe Photoshop certainly did not acquire that expertise within two minutes and understands that gaining a similar level of expertise with Illustrator, InDesign, Premiere Pro, After Effects, Animate, Audition, etc., etc. is likely to take an equivalent amount of time to learn those other applications.  That expert Photoshop user would have a head start in the other Adobe applications as they share similar functionality like Workspaces, Tools, Panels, Preferences, Libraries, Overflow Menus, and so forth.

The expert Photoshop user likely came to being so by having pursued professional training as a graphic designer.  So, the chosen field of study informed the use of Photoshop.  Being an expert in Premiere Pro could result from professional training as a cinematographer, but it's much more likely to come from professional training as a video editor.

Maybe the tricky thing is this:  how does the beginner navigate all of Adobe without training?

Hopefully, that person finds the Adobe Community Forums where there's no shortage of participants at every skill level ready to share their knowledge.  For example, someone looking to take a small video and just crop it and output the cropped area into a new video might get directed to Adobe Express which allows you to crop your video for free.

(For what it's worth, it's possible to export a cropped area of video into a new video with Photoshop.)

Anyone reading this post who is interested in learning more about whichever Adobe application they want to get better at, make note of how each application has a "Learn" option most frequently found on the corresponding Home screen.

Premier is not an iphone or v.v.

Have you tried Auto Reframe?

Yes, Premiere Pro is a very complex app. It's designed for professionals who typically want manual control over everything. Premiere Elements on the other hand is built for "prosumer" use with more automated tools.

And those starting in video post production with Pr Pro get a shock, like you did.

But there are a number of us here most happy to help you get going. Ask questions and we'll answer them.

The reality is the number of daily users of PrPro has grown dramatically over the last few years.

To really learn Photoshop is quite a process. To learn Premiere is even more daunting. These are both professional apps without apology.

And ... as someone who came into video production from a long career as a professional stills photographer, I can guarantee that  video production and stills production are very different things, with very different needs, and very different processes.

For instance most Photoshop effects are naturally built to be applied to one image at a time, or at most, applied to a small batch.

Therefore the processing power requirements on the system aren't really a major concern in building the app or any effects.

For video, there's hundreds of images per minute, with varying framesize and locations on disk that are grabbed and shown simply by metadata. So the system load per effect is a crucial part of the building for each effect and the app itself.

Even effects that may "look" Iike the same thing have to be built entirely differently for Ps and Pr.