Why?

My perspective… the newest characters are mainly for players who have been playing the game for years, and have most or all of the other characters. This means that new characters need to be really hard to get. 
There are literally hundreds of characters for new players to work on… almost certainly including the vast majority of your favourites. 
Some ppl here will complain about how SWGOH makes the money that lets them build the game. I’ve got almost everything in the game and have paid almost nothing. It just takes time but it’s free. 
Regardless, it’s a great game if you don’t worry about always having the newest stuff. And honestly, what difference does it make? If you enjoy building the teams, do it… if you don’t, then don’t.