With the CT system I can monitor the CA's issuance, with DNSSEC I can't retroactively monitor if someone has changed the DANE keys and intercepted traffic.
True, DNSSEC Transparency is not as developed a technology as Certificate Transparency. There has been experimental deployment of such a system[0] but to give higher assurance there is a small addition to the DNS data that needs to be adopted first[1], which is still going through the IETF process.
[0] https://twitter.com/ln4711/status/754516056878772224
[1] https://datatracker.ietf.org/doc/html/draft-ietf-dnsop-deleg...