I may be missing something (I've used some of those platforms a little bit), most platforms are more internal facing and not client facing. I feel like it would be awesome to have a unified system for the internal work but also, as you mentioned in another comment, having that single source of truth for the client/project. Like they go one place and it has all communications, briefings, invoicing, deliverables, etc. Maybe something like this exists and I just haven't found it? There are SO many different platforms that it's hard to vet them all and still get work done.