When it comes to treating destructive chronic diseases like RA, the earlier the better. But better late than never.
Earlier treatment means possibly nipping the disease at the bud to prevent joint damage and systemic complications, and preventing more pathological immune mechanisms being recruited into play, making future disease control more complicated.
I liken this to a house on fire: the earlier you put out the fire, the less damage you'll get; and a big fire is definitely more difficult (impossible even) to extinguish.
Which is why, in late disease, the realistic goal is no longer complete clinical remission, but merely low disease activity. The accumulative damage in low disease activity will accrue to long-term disability.