I currently use the "Favorite" star to mark users who I'm not interested in, for example:
- I asked them for a face picture already
- They didn't reply so it's clear I'm not their type

This means I can scroll the grid and immediately see new potential matches, instead of clicking onto the same profiles every day.

Blocking is an extreme option to achieve this, getting rid of users (basically) permanently, which is not we want to achieve (as we may like to review these users periodically).