Why people play Candy Crush?

When Candy Crush became a thing years ago, I played it for a while and got to like level 100 or something, but then it just became a massive time sink to get much farther, and generally impossible (for me at least) to do without buying extra lives and other stuff like that.

When I read about random moms or whoever getting to some insane level, or finishing all 12,000+ of them? I don't know whether to be impressed or horrified. The amount of time, money and daily grinding to get there is mind boggling. It must be like a full time job.