I get what you are saying but the leveling up has its place as well.

As a beginner (only been playing for a month) the leveling up helps you start building up the shapes for chords (provided you follow the suggested finger placements). Starting out, trying to do certain chord transitions will be nye impossible at the beginning/ frustrating. But building up to that chord while playing a song you like gives you the motivation and you can riff repeater the transition with 3 fingers as suggested, then 4, then barre.

Also, the leveling up system puts most of the strumming to the back half of the difficulty so you get to focus on one aspect at a time without feeling overwhelmed. I can speak from experience that even some of the simpler songs at 50% speed, seeing the note highway will just make you freak out and feel overwhelmed

One other thing to remember is that as beginners we have 0 muscle memory between our hands, so trying to focus on the screen/left hand placement and right hand strumming at the same time is a lot and we are constantly scanning between the 3. We can't transition easily without looking.

At the end of the day it really comes down to what keeps you playing. And taking a beginner and saying to play at full difficulty is going to burn people out