You are right that many (especially younger conductors) tend to conduct scoreless for reasons that are not entirely authentic. But there are others who literally have a photographic memory and it helps them to be even more immersed in the music. I personally only conduct from memory when I can live up to my own standards and be prepared to write out the pie e by hand knowing what everyone plays. In opera, it’s not recommended as anything can go wrong on stage and throw everything off!