It's a pain point for a client of mine that they cannot filter records on the normal object pages (contact list, deal board, etc.) by properties that are on associated objects. I love the ability to highlight those things at the individual record level through association cards and tables, but they want to be able to do this in bulk.
Lists and Reports have the sort of filtering capabilities they're looking for, but those
take more time/knowledge to make than many non-Ops team members have, and
lack the capabilities around editing records, displaying/moving stages, etc. that the ordinary record pages have.
I'd love to see cross-object filters come to ordinary record pages so that our team members can self-serve when they have straightforward questions.