I have a offtopic but related question. Why are our taxes still calculated in stepwise bracket manner. Why not a smooth curve? We have the mathematical and tech

I have a offtopic but related question. Why are our taxes still calculated in stepwise bracket manner. Why not a smooth curve? We have the mathematical and technical knowhow to implement it. Coming back to the Dropbox layoffs, why was this decision a drastic stepwise reduction. Not a smooth curve over a period of say 1 year.