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.