If your DNS panel is the same place you renew the domain, you probably do not have failover, GeoDNS or a one-second TTL. That is fine for a parked name. It is not fine for a shop.
Registrar DNS is a bundle
It exists so the domain works on day one. It is not staffed or built as a global anycast authority.
Managed DNS is a product
Cloud DNS: 210+ Anycast servers, GeoDNS, weights, health checks, CNAME flattening, DNSSEC, IPv6, vanity NS, API, one-second minimum TTL.
Cut over without touching the website
Import records, preserve mail, change NS. Point the site at Cloud CDN in a second change when you are ready.
The giveaway tickets
Cannot lower TTL, cannot flatten apex, cannot health-check, cannot answer during a flood. Those tickets are the product gap.