Device attestation is a system that lets an app check whether the phone/OS is deemed secure. This is in general not a bad idea, if say the attestation reports the OSs patch status and you would get a warning within the app.
But apps usually do not show a warning, they refuse to operate.
Furthermore the checks include unlocked bootloaders and rooted devices. While both have a security impact, locked bootloaders are a way to keep you on your pre-installed OS and disabling root is keeping customers from owning their devices and mitigating the security issues that come with app stores and all the bad apps you find there.