The question is what you mean by "have everything on alot of belts". In the broadest sense, what works reliably are belt buses. Just have one belt per product (or a few belts per product) and then split/send them wherever you need them. No filtering/sorting necessary.
If you want mixed contents belts, there's major problem with them in the game but it's not due to lack of sorting/filtering. It's due to lack of excess management. If you send two products over single belt and the consumption and production rates don't quite match, one product will eventually block feed the other product entering the belt and reaching its consumers. And if you extract the excess at the end of the belt, you have nowhere to send it to - the best you can do is to route it back to the belt start. But there it will be merged with more of the product until the belt will eventually fill up with the excess product, blocking the other product again.