Does anyone know why we need to have the withdrawal blood week on the pill? Why can’t we only take active pills and never have periods again?

you can take active pills non stop, you don’t need to take a break

I don’t know who told you that but that’s not true at all. The pill was designed to never have a break, but for the church to be accepting of birth control it had to mimic a natural cycle (it is not a natural cycle). Break weeks cause a lot of user error so feel free to never take break weeks if you wish. If you get yours from insurance be sure to check that they cover the additional refills you will need.