Why can't I filter on whether the sitter limits for crate-trained pets?

You seem to be addressing your comments to Rover. However, they do not come here. You should try calling their customer support team and have them document your suggestion. The number is [Edit: Rover’s contact options have changed. Visit the Rover Help Center at https://support.rover.com/ to find the phone number, help articles, or chat with the team]. BTW, I've never heard of Rover asking either its sitter community or customers for improvement ideas or problems noted. They've hardly made any substantive changes to the platform since it was launched.

To have rover consider adding filters (which likely most sitters and pet owners would benefit from), please call them at:[Edit: Rover’s contact options have changed. Visit the Rover Help Center at https://support.rover.com/ to find the phone number, help articles, or chat with the team]. The search parameters available leave much to be desired. There is a small chance that Rover staff have the ability to search using more filters than all other users.So you may consider asking them to help you with the search.