LinkedIn Recruiter is access, not workflow. What you pay for is the search index over the largest professional network in existence, InMail credits to contact people who never applied anywhere, and filters over profile data nobody else holds.
For sourcing passive candidates there is no genuine substitute. If your hiring depends on reaching people who are employed, content, and not looking, that reach is the product and every alternative is a compromise on it.
The friction is cost per seat, InMail limits that make outreach a rationed resource, and the fact that it stops at the conversation. Once a candidate replies, everything after: screening, interviews, pipeline, decision, happens in other systems.