jkoseattle
I don't think it's a matter of whether notation view is viable or not. While I agree that traditional notation is not going away ever, the way computers work doesn't lend well to it, which is why it's not great for a DAW. Notation has always been an approximation of the sound, operating under the "well, you know what I mean" paradigm. Baroque composers would put a squiggle over a note which meant "do some sort of trill thing" and just what that was was open to interpretation, by design. Computers are terrible guessers, they are strict literalists, so that every last thing has to be spelled out for them. Traditional notation just doesn't work like that, which poses three unsolvable problems: 1) Traditional notation doesn't contain all the information a computer needs to play the music correctly, 2) There is a lot of information in the music that notation can't communicate, and 3) the exactness of computers eliminates the "you know what I mean" aspect to notation, leading to things like whole notes tied to trailing 16th notes.
BUT... what notation does provide elegantly that any DAW would be capable of reproducing is a clear picture of what's going on in every instrument at any given time. Track View comes closest to this, by having each instrument on its own row, but it falls short because of how clips get made and rendered. (i.e. you can have clips with no notes in them, or a clip with a bunch of legato repeated 16th notes looks identical to a clip with one long note in it, etc., etc., etc.). PRV usually fails in this, because instruments all occupy the same vertical space, so there's a lot of overlap.
Combining PRV and Track View into a new view designed to solve this problem is totally possible. Imagine PRV with separate rows for visible tracks, and a dynamic Fit Content option which fits visible content and adjusts all the time, so that most or all notes are visible on-screen no matter where you are in the piece. Add to this a gradient background, so that low notes are displayed on a darker background than high notes (instead of having to look at "C3"). And the view would always show all tracks that currently have notes in them and hide those that don't.
Your suggestion for a new view combining staff and prv is very interesting. It makies me think of Cubase. Cubase's track view is interesting in that it has little notes in it, showing the vertical and horizontal relations in the musical content. But you can't select a subset out of the whole, or at least I don't know how to do that. Still, there is the consideration of ranges of instruments. The great usefulness of a stave is that you see exactly what the notes are. This allows you to instantly pick out mistakes, like having the violins playing an F on the bass clef, which is below their range (they only go down to G, unless you use scordatura, having the player retune the string, which is pretty unusual). If you're arranging a string section, you need to see all the five groups (two sections of violins, plus violas, cellos and basses). This lets you make sure you have ranges correct, but also how well the parts fit together. Of course, your ear is the final arbiter here, but the visual matrix of notation is indispensable for most composers. And yes, there are composers who prefer working in a DAW vs a notation program. Especially ametuers or hobbyists, who need the feedback of decent sound to assist with their orchestration.
I think your idea has merit and I hope somebody picks up on it. A new synthesis, a new paradigm even, of how to display music in a way that all musicians could use, both notation types and prv types, would be a game changer.