I actually find his posts really amusing. Broadcasting this level of idiocy is rare and highly entertaining.

The only potential drawback is that he might scare off new users of the forum, who are seeking help, by infesting their threads as has already happened a few times...

Acting in my capacity as Community mod for a moment: Please refrain from insulting other users.

Randomly click on everything and eventually you'll beat the game.

I don't use discord, so I'll answer here.

Firstly, are you still here? I'll assume you are.

Secondly, on to business (there might be someone else with the same doubt).

The "standard UI design" people are talking about is: point and click. You have itens represented as icons and spaces to put them, and you have (important) MULTIPLE SCREEN TYPES.

The game screen (with the chars - called dolls - and grass/floors/etc) is the main screen, and along the left edge are shortcut icons to the other screens: map, journal, inventory, character sheet, save/load/options, etc.

To equip the sword, you have to pick it up on the game screen (or buy in a store, but this is more advanced and a topic for an advanced lesson). Point and click on a container where there is a sword/dagger/staff/whatever. The char will move and open the container, and you'll see at the bottom of the game screen a list of itens inside the container on the left-center bottom, and a list of your inventory on the right-center bottom. If you click the sword icon on the left, the icon will transfer to the right (inside your inventory).

Once the item is in your inventory, YOU MUST CHANGE TO ANOTHER SCREEN, THE INVENTORY SCREEN. Click the icon that looks like a backpack, and the screen will change to the inventory screen.

After the inventory screen opens, point and click the sword icon. This click (don't hold or drag, just click) will pick the sword up. Another click in the same spot will put the sword down back where it was. Once you have picked up the sword, move the cursor (that should have changed to a sword pointer after you picked the sword up as above) to the slot besides the char picture and click the slot: the sword will drop in a slot where the character will equip it, and the char picture should reflect that.

Now you should have a sword equipped. To use it: find a character in the game screen with a red circle beneath. This is the sign that the character is an enemy. If you pause (easier to point the mouse in a stactic screen) and move the pointer over the red circle, it will change to a sword. If you click the red circle with a sword pointer, you'll tell your char to attack the red circled character.

That's all for the first lesson on how to use the sword. I hope I made myself clear on this.

Any doubts?

At around 4:17, he complains about the Outer Worlds tutorial, and how it's holding your hand too much. Which is the exact thing he is asking for here.

"The point that you have here is you're now setting the player up to expect every type of basic instruction under that context. So I'm supposed to be so a player (sic) hasn't played this is going to be expecting every single key basic element to be popped up with a box with some form of button or keybind, or whatever else it is, with a detailed instruction"

I've come to the conclusion that he is just another guy trying to make a living by being publicly rude and negative on the internet. I'd avoid giving him my clicks.

That's not complaining about hand holding, it's complaining about a lack of consistency in instructions. It prompts you on how to walk but not to turn the camera. Most games actually do both in the form on calibrating or to set the up/down mode.
He later mentions how the player is supposed to know to use jump to drop down a cliff safely. I don't know many games with that mechanic.