Chinese 达人 existed classically meaning "a person who understands life / a sage" (as in 《论语》 "己欲达而达人"). Around 2000 it was reborrowed via Japanese 達人 (tatsujin, "master of a skill"), and the new sense — an everyday expert — now dominates.
usage
On Douyin, Xiaohongshu, and Taobao, 达人 has become a formal label for recognized influencers in a niche: 美妆达人, 健身达人, 美食达人. The platforms even run 达人 recruitment programs.