That's so wrong, I don't even know how to approach it.
1) Lack of low-level balance absolutely trashes new players, therefore, player retention. This is literally a game-killer! Low player retention is the #1 reason for games to be canceled!
2) It absolutely destroys any semblance of copy-driven progress. It's far harder to learn by experience, making more effort necessary. And most people already put in way too little effort. You would see even LESS players with any decent skills at high levels, simply because their understanding of the game would be skewered.
3) It promotes toxicity. Players would be excluded for being too weak/too new. The difference between the "new" player and an "old" player would widen the already wide gap of "crap player" and "good player". And "new good" player would think he's crap simply because he met a "decent old" player that outperforms him...even if he plays worse.
4) It invalidates most of the content. Even now the dungeons are too worthless. Their experience sucks. The items they offer are useless. They are too easy. They should be made more demanding, not less! A scholar in Sastasha literally NEVER needs to use a single heal if the tank and DPS are decent. The fairy is enough. That's how easy early content is due to the syncing not being harsh enough. I dare say that older content could actually be lot more fun, even with limited tool kit (if that limited tool kit still did include some AoE...) IF it would demand players attention.
Early-stages balance is absolutely crucial. As much, if not more so, than end-game balance. Literally everyone will go through it and it's what makes or breaks a game for someone. By the end players are more willing to forgive lack of balance since they are attached to the game, friends or whatever. Not to mention there's always the possibility that the next update will change it in their favor, since end-game is frequently changing in ALL MMO games. Early-levels don't have that luxury, be it in practice or in hopes.