I remember reading them back in the early 90s (Robin Hood: Prince of Thieves, Far and Away, Back to the Future). They don’t seem to be a thing anymore (or am I just not noticing them).
As an aside I remember liking them but I was a preteen at the time so maybe they were terrible and I just liked the movies.
Marvel made some of its movies into kids books recently, I think I saw Far from Home and winter soldier for Probably age group 8-10 or something like that.