Oh ... Where to begin. I can write an essay on it, but just to name a few:
1. There's a button on my M3 Mac keyboard that says 'delete'. It deletes stuff everywhere else, but welcome to Finder, this simple button doesn't delete a file or a folder. They thought giving it a two/three keys combination was a better idea.
2. Similarly, they thought you rename file/folders more often in a day than you open them. Why else would they make you press two keys to open one, and the most common single button in the world to open files (Enter/return) to rename one instead?
3. No 'Cut' (I know the alternatives). One might find it surprising but there are fans that defend even this move - they say it's because this is more "intuitive". You only copy everything first and only at the time of pasting you decide whether you want to move it or copy it. I say, if that's really the case, why does every other app and Editor (including the ones made by Apple) have a Cut option? Why don't we always follow this more intuitive method of "copying" first and then pressing the Option button while pasting. Let's remove Cut from everything and see how intuitive people find it.
4. By default, the Finder doesn't even tell you where you are. That's a basic requirement from a File Manager. Sure, fiddle with the settings and at some place you'll find an option to kind of enable that.
5. No option to quickly create a text/other file in a given folder. If you've struggled enough and enabled the view where you're able to see where you are at the moment, there's a _chance_ you'd also see that from that view you can actually go to Terminal directly in that folder. Go there, and type `touch ` to create a file in that folder.
6. You got a full path to go to somewhere on the disk. You quickly open Finder. Oh, the default view doesn't even have a place to paste it and hit Enter. Who could have thought to hide it? Same problem with the native 'File Open' dialog that's used by all the other apps on the system. Even if you have the full file path, unless you go to settings you won't find a way to go to that file directly.
7. No easy (if at all) way to persistently map a network drive that automatically remaps when the network drive is available. You have to keep connecting to the SMB server again and again.
8. Side bar folder shortcuts get removed when the folder is deleted and recreated for any reason. You have to recreate them. Not sure who made all these decisions or if they were even thought about.
9. No straight way to even 'Refresh' the files in a folder. Try going out and in, closing and reopening Finder and just 'hope' that it will update and show the newly created files or changed file properties outside. Many times it just doesn't.
10. 'Get Info' allows you to also 'Set' (a lot of) Info. This is UX 101. They could have just named it `Properties` instead.
11. Hell, you can't even maximize this app window by double clicking on the Title bar, unlike for example another Apple made app 'App Store'. No consistency.
12. In List view there's no padding, I can't even find a place where I can right click and paste a previously copied file in the 'current folder', without it hitting a subfolder and pasting the files into that instead (assuming the folder has many folders inside). I'm surprised no one found it in internal user testing.
These are just off top of my head, I'm sure I can find more if I spend some time. There might be involved solutions to these, but there's no way we can call this an 'intuitive' interface. And this is just one application in the whole Operation System.