The point is you save a lot of time. This is one thing that is not there, yet it is more important than 99% of all the other "quality of life improvements" ( or whatever they call them ) they have added.
That is exactly what I do, delete a whole animation then add a new one, but being able to select multiple frames ( the most basic thing in any animation software ) saves a lot of time when you have animations with a lot of frames.
Sometimes you want to delete 40-50 frames and leave 10 in there. Deleting everything and importing new frames is still faster than creating a new animation, renaming it and setting frame speed, image points, collision polygons, looping etc...
Just sayin'. There are a lot of improvements advertised which make practically no difference compared to this one and it is just absurd something so basic still isn't there. That should have been in there in 1985, that is how basic it is.