For top cultivators, being able to quickly enter the Hua Mansion stage provides an indispensable advantage, as it allows them to overpower their enemies who haven't advanced yet in a short period.
Of course, if viewed from a long-term perspective, the talents of top cultivators are generally not too shoddy. Even the "top tier wall" Chen Lingyun, when placed within the entirety of team monks, was above average. So, everyone would eventually reach the level cap and then equalize with each other — assuming they could live that long.
In foreign supernatural realms, where the strong prey upon the weak and competition is ruthless, those in the top flow are essentially rushing to level up, even at the cost of mortgaging their future, because having a future at all depends on staying alive.