Not just Apple. Windows 8 and beyond horrors aside, I have this friend of mine to whom I already installed three Linux machines in the past (1 x XFCE and 2 x Mate) who was 100% satisfied with them. Having brought a new faster laptop for reinstall, I wanted to give him something prettier which wouldn't slow down. Turned out he came back frustrated because of the asinine way KDE Plasma desktop menus behave, literally hiding things from view based on mouse position and not following a click, which is against every rule of good UI programming.
Please stop following bad designs just because they're new and/or come from big names; Windows XP UX still beats everything out there both in usability and intuitiveness. If users have to read a manual even to do the most basic things with a new user interface, I call it a failure.
When I was 8-10, I absolutely sailed through new programs in Windows XP. Now that I'm 25, every new thing I want to do in a "new" app (Discord, Slack, Facebook, Zoom, etc.) is precluded by "Google, how do I..."
There's so little conceptual integrity in modern applications. I can't stand it.
Since you mentioned Discord and Slack together here, I have to point out that one of the worst design choices a company can make is hide CRITICAL interaction elements behind a hover state.
Slack and Discord are both incredibly guilty of this. Lots of important things that you do everyday is only visible to the user if they are hovering over a certain element on the page. For some of us this isn't as big of a deal. For me, I tend to move my mouse around as I investigate a UI and try to figure out how to do something.
But when I watch my mom interact with a website, she works entirely differently. For example if she wanted to edit a message, she wouldn't naturally hover over the message and see the gray pencil appear on the far right of the message in a light gray bubble, and then think to click on the pencil. She is looking for something that says "edit". And she will stop, lean back, take her hand off the mouse, and start looking around with her eyes to the various parts of the app. She will NEVER find the edit button. Even if she is hovering she would probably see the pencil and not have it register that the light gray pencil means, "edit".
Furthermore, neither of these apps like to use "buttons". So when you do various things like editing a message or writing a room description, and stuff like this, they just assume you will press the ENTER key. There is no button to save or submit. In discord, light gray text shows up on the bottom that says "Press ENTER to save", but many people won't notice that.
Zoom is equally guilty, but not as bad. Zoom seems a little more logical in most places and they tend to use brighter colors on buttons and messages as opposed to Slack and Discord that want to use 50 shades of gray (and not in the sexy way) as the color palette throughout their app. Although I will admit, about once a week I forget how to leave a Zoom call. Zoom makes it far too complicated to do something that every Zoom user will do on every Zoom call, which is inevitably leave the room.
Please stop following bad designs just because they're new and/or come from big names; Windows XP UX still beats everything out there both in usability and intuitiveness. If users have to read a manual even to do the most basic things with a new user interface, I call it a failure.