Bifurcation isn’t going to happen, might be nice if it did, but I don’t think so. Baseball didn’t have to do it and I don’t see them having to build new stadiums/fields with 600ft fences to accommodate the evolution of the game. Golf has a real problem. WG and others don’t think the distance problem has impacted/hurt them but it has. It is making the game more expensive for all of us. You might only play the 6000 yard tees but there might be 1500 more yards of golf course behind you that someone had to build and maintain (and pay for). If you play there, it is YOU who is paying for it. College or even high school kids who hit it 330 don’t want to come play chip and putt on your 6500 yard golf course. They will go somewhere else to play and practice. Maybe you don’t care but you should. This impacts all of us.
On another thread I suggested 10 par threes. What is so special about par fours that you need ten of them instead? This might be the easiest solution out there 
Isn't the equivalent little league fields, softball fields, etc?
Interesting point. Maybe if courses charged by the yard played, golfers would more readily move up a tee! Make the true back tee players pay more. Someone ran the math once. Because all would pay for greens and Fw, etc. and you might have native grasses for much of the distance from tee to fw, they thought the back tees only added 5%, maybe up to 10% more in maintenance costs. While that doesn't sound like a lot, if you say the maintenance budget went from $1M to $1.05 or $1.1 Million for the 400-1000 extra yards above 6800 from the next tees, I think many courses are looking for ways to save $100K per year in maintenance to balance the books.
Yes, some top players (still less than 1% of golfers, maybe less than 0.1%) will go somewhere else. If it is 1% of 30,000 golfers, that is 30 golfers a year. If they pay $100 per golfer, or $3000 in revenue, that is less than the minimal 5% cost extra for their yardage. $50,000-$3,000 is a $47,000 net gain for the course, assuming all savings are implemented.
As to your par 3 concepts, I have long thought the par 4 was the most efficient golf hole. A set up shot to determine what conditions you have on the approach that might affect your score, followed by an approach shot (the key shot) that determines how many putts you might take.
The second shot on a par 5 is inherently less interesting, because there is rarely a need to set up the set up shot.
And, on par 3 holes, you get to play the key shot, but more or less dictated as the same exact condition for you and your partners (assuming you play the same tee.) It is one less chance to differentiate yourself, which of course is the name of the game on any hole, particularly in match play. I gathered the 3, 5 hole types were found necessary for connections on other holes, or lack/extra land somewhere. Maybe someone said, "Par 4 holes are great, but in the name of variety, lets make a few par 3 and par 5." A few somehow morphed into a standard 4 each in most cases.
The easier case to make is get rid of at least 2 par 5 holes (USGA has been doing it for 50 years or so in tourneys).
I did have a client who wanted to build a "second shot" course, all par 3 holes, but each time you went around (it was 9 holes) you played from a different area. Not a tee, per se, more like a fw, and you lined up left right, sidehill Left to Sidehill Right, etc.. The goal was to teach you the ramifications and advantages of placing your tee shots to different locations in an effort to educate on strategy.