What is confusing is that there is no more little squares to represent layers.
You have to display collections panel in sidebar or use outliner.
That 1,2,3, etc… keys are no more available to manage collections visibility, except in object mode.
People using them in edit mode may be frustrated by that.
But when you want to move an object to another collection, you use exactly same shortcut as in 2.79 to move an object to another layer.
This not complicated to understand. That should be easier for a blender user to use than for a newbie.
Amount of collections is infinite. There is no 2.79 way to represent that.
2.79 have to adapt or if they have smart ideas to share them.
Just complaining that is not the same will not solve their issue with this huge improvement that will not be abandoned.
Your remark about photoshop is not pertinent.
What is the interest to keep an artificial separation between layers and groups ?
Take a look at physics settings and render settings in 2.79 and 2.8. But merging both in 2.8, you get rid of lots doubling restriction to groups and layer sets.
If he wants to keep such separation, a user can name collections used layers with a layer_ prefix and collections used as a group with group_ prefix instead.
Here again, that is not complicated at all to deal with it.
There are problems with collections. Lack of work on nested collections and bugs about relinking.
Stable 2.80 was not released, yet. Documentation and Tutorials should not be spread before changes to outliner will be completed.
That is unfortunate that 2.80 release is scheduled before the end of GSOC about that crucial element of UI. That is a little bit ridiculous. People will make tutorials about 2.80 and then, outliner will have another figure in 2.81.
That is not true. Exactly, same panels are there.
We just lost tabs to separate slots/ brushes/ mode options. They were fused.
Some options are now hidden into sub-panels.
But exactly, same functionality is there.
You may think that UI sucks in Texture Paint mode. That is slow and is a waste of space to repeat same Brush panel settings everywhere (Topbar, sidebar, properties editor and right click menu).
But if you losts something, say it. That is not supposed to happen. You should be able to have same functionality in paint mode and sculpt mode in 2.80 than in 2.79.
Although UI is not the same ; if it is not the case : that is a bug, not a UI design choice.
In theory, there is no major replacement without big improvements.
Blender Internal is replaced by EEVEE. EEVEE is a big improvement.
Layers and Groups are replaced by Collections. That is a big improvement.
File organization is now relative to names of collections instead of little squares sets, hard to remember.
There are assumed removals like BGE one.
https://wiki.blender.org/wiki/Reference/Release_Notes/2.80/Removed_Features
There is lost of baking to vertex color that is not mentioned under Release Notes.
But except this one, you should be able to do exact same thing in 2.80 than in 2.79.
If you know something that is missing from 2.79, say it. Even if developers have no time to include it in 2.80, it should be mentioned into 2.80 Release Notes.
Target of 2.80 is to clean-up UI to be able to add lots of new features in future 2.8 & 2.9 releases.
2.79 UI is crowded. You can’t add more things to that and keep space for addons.
Target of 2.80 is to make blender usable by using only a graphical tablet without keyboard.
That is not just an UI theme that would solve 2.79 UI issues.
And if they neglict topbar and use 2.7x keymap, 2.79 users to be able to work immediately in 2.80.
I am not saying that is easy to adapt to a new release that have equivalent of 3 or 4 Blender release improvements and changes.
But seriously, there was a huge work done to help 2.79 users to make transition.
And that will be continued when 2.80 will be released.
Then , UI discussion will continue after until 2.81, and after 2.81, and after 2.82… that is a never-ending story.
If you want to criticize choice that have been done ; of course, you can do it, now or later.
But try to be fair and explain precisely what is not working.
Because if you stay vague, there is no chance that your opinion would be taken into account, seriously.