Start from arithmetic, not identity: your hourly value doing billable work versus the cost of competent help. An owner billing $150/hour who spends ten weekly hours fighting Google Ads is paying $6,000 a month for amateur marketing.
The hybrid that usually wins: own the strategy and the assets (accounts, site, lists — always), do the parts only you can do (reputation, referrals, being the face), and buy execution for the technical lanes where experience compounds — ads, tracking, deliverability.
Whichever way you go, the free-tools era means DIY is genuinely viable for the disciplined: the playbooks are public (ours literally are). The scarce ingredient isn't secrets — it's consistent weekly attention.