Traceroute defaults to IPv4 addresses even when IPv6  addresses are available. While there is the traceroute6 option, The RFC below appears to indicate that this should not be the case. 

RFC-3484 - Default Address Selection for Internet Protocol version 6 (IPv6) https://www.rfc-editor.org/info/rfc3484

Traceroute outputs from RHEL 9 system:

[root@Kombat9 ~]# traceroute kernel.org
traceroute to kernel.org (139.178.84.217), 30 hops max, 60 byte packets
[root@R9 ~]# traceroute6 kernel.org
traceroute to kernel.org (2604:1380:4641:c500::1), 30 hops max, 80 byte packets

Ping output showing default to IPv6

[root@R9 ~]# ping  kernel.org
PING kernel.org(dfw.source.kernel.org (2604:1380:4641:c500::1)) 56 data bytes