For most people starting out, shared sending (through your own SMTP provider like Gmail/Outlook, or a transactional provider) is actually the better choice. A dedicated IP with no sending history has zero reputation of its own and needs the same warm-up work a new domain does — except now you're solely responsible for that IP's reputation instead of benefiting from an established shared pool. Dedicated IPs make more sense once you're sending consistently high volume (tens of thousands+ per month) and want full control over reputation independent of other senders.