Why doesn't "Cloudflare 1.1.1.1" compress root answers?

At first I thought they had disabled compression: bjorn@miraculix:~$ dig . ns @1.1.1.1|grep SIZE ;; MSG SIZE rcvd: 431 bjorn@miraculix:~$ dig . ns @8.8.8.8|grep SIZE ;; MSG SIZE rcvd: 239 bjorn@miraculix:~$ dig . ns @9.9.9.9|grep SIZE ;; MSG SIZE rcvd: 239 But then I noticed that they *do* compress other names: bjorn@miraculix:~$ dig net ns @1.1.1.1|grep SIZE ;; MSG SIZE rcvd: 253 bjorn@miraculix:~$ dig net ns @8.8.8.8|grep SIZE ;; MSG SIZE rcvd: 253 bjorn@miraculix:~$ dig net ns @9.9.9.9|grep SIZE ;; MSG SIZE rcvd: 253 Which just makes it even more confusing. What's so special about root? Except for the obvious :-) Bjørn