It's even more frustrating on guitar where the literal same note in the same octave appears all over the fretboard. You have to figure out all the notes nearby to figure out what position you should be in. Even with years of experience I find tabs faster
The flip side of this is that chord shapes (in terms of hand shape, not intervals) are constant on the guitar (assuming no open strings). Learning piano after guitar, I was intimidated by the fact that – for example – an Am and Bm had different shapes, whereas on the guitar it's just the same shape transposed up the neck.
Anyway, I've noticed some music youtubers can read and write midi notation just as fluidly as sheet music. Which can result in some fun shenanigans[^1]
There's a lot of same shapes on the piano as well.
And the differing shapes are a bit like how A major and C major have different shapes on the guitar isn't it, for practical reasons you don't use the same shape for those two.
With the clarification that the same shape of the C major chord on the piano, when you move it up through the scale, the same shape produces all the diatonic three note chords of the scale, i.e C, Dm, Em, F, G, A, Bdim, C etc.
It might be, but it also might not. If you're just cowboy chording, sure, but if you're playing chord melody you'll find the chord you choose is highly contextual based on what you're playing and where you're going. An Am chord is a continuum of notes going up or down the neck A-C-E (G?) over and over-- wherever your hand sits, there's an Am available to you. It just might sound better (or more interesting!) or play easier to grab one set of A-C-E versus another.
I think the parent meant that those voicing are still the same when transposed all over the fretboard. E.g. the first inversion of a V7 has the same shape for all the notes horizontally. To go from A7 to B7, you just move two frets. And if you move vertically, the shape is slightly changed, but still recognizable enough.
A guitar has to be the easiest instrument for transposition (or maybe it's just the one I'm most comfortable with!).
Until you reach the B string. A shape that works on strings 4/5/6 does not work on 1/2/3. This is because G->B is 4 half steps, the rest of the strings are 5 half steps apart. So you need 2 forms for closed chords.
Then you move that note a half-step. The rest is the same. And actually, if you use drop-2 voicing, there are 3 forms because of that half-step, but still the overall shape is pretty much the same. You really need to remember one shape, and then adjust it accordingly.
There's no standard Midi "notation" that's human-readable/writeable AFAIK - even written out in, e.g. hex, I would be flabbergasted if anyone could perform from a displayed Midi file.
The YT video appears to show a piano-roll type display (common for DAWs etc.), nothing to do with midi (which doesn't even have the concept of notes or note lengths at all).
Tabs are bad because they lack a sense of timing that sheet music has. I’d recommend going with a powertab or guitar pro file as that will show you the standard notation as well as the tablature. Many printed guitar sheet music books are also formatted like this. That being said knowing what sort of positon to play a note depends on what you are going for. You are right that you can play a single note all over the neck, but for a lot of those positions it will be awkward to get to the next few. Knowing your chord shapes and scales helps make this intuitive and automatic.