[TrailMixRaisin]

Of course there is still trust involved. Every time you cooperate with somebody else booth of you have some assumption what the other will do. You trust that a webshop will send you your product after you have bought it, etc. To give a foundation for this trust we have laws. It would be illegal to sell you a product and just keep the money without giving you the product.

This is the same with data protection and GDPR. They could just say that they deleted it and keep a copy on their own. BUT using such systems or asking them (in a documented way) to delete your data is a really strong signal from your side what your assumptions are. This will make the fines much higher if a data protection authority would find out that a company kept the data when you have already shown your strong request to delete it. So in a way these mechanism should make it easier for you to trust the other side to do their part because the fines will just get bigger.