The "gather resources yourself" stage is like the first 5 minutes of the game, more so to force people to automate; I actually think it's an intentional stylistic choice to demonstrate how they are different. Like the first technologies one gets automates all of the resource collection in the game (and later tier resources can't be collected by hand). It becomes a pretty good point and click strategy game very quickly. In fact after the first couple hours you can basically play the game from the map screen if you want, using blue prints to put down large buildings and spidertrons as units to move around, without moving your main character ever again.
Like this is how the mid game looks (user designed blue prints, bots build it automatically, etc): https://www.youtube.com/watch?v=M0k1YeMm-6o
That is PAINFUL in Factorio for a reason. It forces you to automate it away as soon as humanly possible. Which is the point of the game.
There's also a mod called long reach[1] which allows you to do most things without walking around. If you want to give the game a second chance I'd look into that.
To give an analogy with programming. The demo is more like setting up your programming project, which can be a bit tedious. While the normal game play is more like thinking about the software you're building, defining good abstractions, thinking about how to structure your code both on a macro and micro scale, keeping things DRY etc
They've actually changed the early game so this part isn't necessary anymore (assuming you're talking about mining ore).
Because thats not what the game is. If you want that, play something else.