A general contractor performs the renovation work — they employ or subcontract the trades, and they're financially motivated by the project's scope and pace. A renovation project manager doesn't perform the work themselves; their job is to represent the owner's interests throughout the process — sourcing and bidding out the work, coordinating the trades, and verifying it's done correctly before payment is released.
The distinction matters most at the exact moments where interests diverge. When a contractor confirms their own work is complete, there's an inherent conflict — they're grading their own test. When a change comes up mid-project, a contractor's incentive is to price it favorably to themselves, since you can't easily shop it around once demolition has started. Neither of these is dishonesty exactly — it's just how incentives work when one party both does the work and judges it.
A project manager's value is structural, not just supervisory: running competitive bids instead of accepting one quote, negotiating contract terms that protect the owner before work begins, and bringing in independent verification — someone who isn't the person doing the work — to confirm each phase before payment.
For an owner who's local and available to check in regularly, a strong general contractor alone can work well. For an owner managing a renovation from abroad, the gap a contractor-alone arrangement leaves — no one independently checking, no one negotiating on the owner's behalf — is exactly the gap a project manager exists to close.
Neither role replaces the other; a project manager typically still hires and coordinates contractors and trades. The question isn't "contractor or project manager" so much as "who is representing my interests specifically, as opposed to their own" — and for a renovation you can't personally oversee, that answer matters more than it might for one you can.