at least this is going to be the last of Lee Jieun as a major singer. She might still release an album every 2-3 years, but by that time her stranglehold on Korean Pop would have lessened significantly.
You keep hoping, she keeps disproving.
But yes, it is typical for music careers to slow done with age and now with her ear problem yet not healed.. she may slow down. She has already said she wants to slow down in her 30s.
As to the "stranglehold", will it loosen if her music has longer pauses?
Not necessarily, if she remains in public eye, in other ways, acting, hosting etc.
We will have to see.
In any case, she has set enough records and made enough impact in S. Korea, that won't be overtaken in the near future.