The SVCB and HTTPS resource records allow you to speed up your time-to-first-packet (by basically stuffing the Alt-Svc HTTP header / ALPN TLS extension into the DNS); let you do redirection on the zone apex without using CNAMEs; allow for simple DNS load distribution and failover; obviate HSTS and the cumbersome preloading process; and enable stronger privacy protections via Encrypted Client Hello aka ECH