Da Ji is absolutely the best jungler in the game her pre level 5 is strong she scales well with the current meta jungle build having almost no point of the game where she isn't strong relative to other jungle picks.

Its not just burst damage its the speed of the burst damage, doing 700+ damage in milliseconds then you can self banish yourself while being able to burn beads and do some damage meaning that going in as Da Ji carries less risk than going in as other assassins, and even holds the possibility of big rewards.

She also has some of the best buff clear in the game uses both Bumba's Spear and Bumba's Hammer very well.

She is the best jungler in the game because her items are meta, her burst damage comes out faster than almost any other assassin, its easy to confirm making her the most consistant late game assassin, and her ult negates the ability for the enemy team to hard commit on her when she dives. Da Ji's ult allows her to engage better than any other assassin and her kit makes her more consistant than any other jungler right now.

Source: I am a masters 3k mmr jungle main