I will make an anime animation

Its because we have to Draw drawings every for every frames.For example for 1 seconds (2d animation industry runs at 24 Fps) there are around 12 drawings or more in one second.So Colouring every drawing every frame takes a lot of people to make

It really depends on the duration of animation.Even professional animator with over 10 years experience take average 6months-a year to produce a anime quality animation of 1:30 minute

I worked in few animes (but only as a inbetweener) my seniors usually get Genga works per scene content.3 weeks deadline for 7seconds genga with line cleanup and compositing guide lines