"Not remotely accurate" means "the exact damage numbers are wrong"?
The creators aren't going to change the game because some YouTuber thinks gameplay happens in featureless voids where only one set of circumstances are ever in play. (Even if said YouTuber openly encourages his followers to harass and spam the creators because they didn't give Monks 3d6 attacks.)
What you seem to not understand is that you can't discuss DPR in a vacuum, or without taking normal factors of gameplay into a result. Any white boxing of just DPR shows monks falling further behind as they level up, and it isn't close. That isn't even worth arguing with you about; I encourage you to look up the relevant math as it has been done many times.
But at a very basic level, consider that the value of each combatant essentially comes down to damage done AND damage nullified or tanked. So let's just look at a level 1 barbarian and a level 1 monk, and we'll put the up against the most standard of level 1 foes, the goblin (+4 to hit, 7 HP, AC 15).
Monk is +3 dex, +2 wisdom, +2 constitution; AC 15, 10 HP. Barbarian is +3 str, +2 constitution, +2 dex, AC 14, 14 HP. So the monk's DPR against the goblin is 7.15. The barbarian's DPR is 6.6. The goblin's DPR is 2.75 vs the monk, 3.025 vs. the barbarian...except the barbarian is raging, so that gets cut in half and then round DOWN to the nearest whole number, per the rules. So the goblin's actual DPR against the barbarian is a flat 1.
If it's one goblin, both monk and barbarian basically kill it in one round, and though the monk takes a much larger percentage of their health in damage, it's not much of an issue. But when is it ever just one goblin?
So let's white room this into an ongoing stream of goblins and the difference in value to the party between the monk and barbarian becomes stark. The monk survives 4 rounds, delivering 28. 6 damage while tanking 10. Net value to the party is +38.6 HP in this scenario. The barbarian survives 14 rounds, delivering 92.4 damage and tanking 14, so has a value of +106.4 HP, around three times the value of the monk. Note that if the barbarian never rages they still come out on top but it is much closer, as their value drops to 47 HP.
So who is actually the better damage dealer, and which do you want in your level 1 party? Unsurprisingly, the barbarian is going to be much more valuable. This tracks with what you experience at the table - if the monk tries to tank a group of goblins they are going to die fast, while the barbarian can keep going.
You might argue that the monk shouldn't be tanking, that they are a light skirmisher. Okay, so what is the value added there? To begin with, you have to have a tank; a light skirmisher is a non-essential element. In general, ranged combatants can do the job more efficiently. But even among light skirmishers, the monk is a poor cousin to the rogue. The one really good monk trick, stunning strike, was heavily nerfed in the last UA, with nothing much added to replace it.
So we have a class that gradually falls behind on the DPR curve until at high levels it isn't even in the running unless you play a Mercy monk, which barely keeps up, has a secondary niche at best, and isn't even the best class at that niche. Which is why monk is getting yet another redesign in the next UA.
There's a reason that the monk is pretty universally regarded as the weakest class in 5e.
Edit: My numbers are a bit off because I forgot to factor in critical hits but the 5% makes no difference in the end results. Also note that we could swap in a paladin or fighter and get mathematically similar results to the barbarian, with their high armour absorbing a similar amount of damage as rage.