i'm sure that's a fine setup for the average home user but devices that use proprietary firmware like that aren't conducive to a security-first design where you hold all the keys. because it's designed to be secure, even from you, it always has an asterisk on it (network is secure* according to eero). that and you have no way of verifying what data it's phoning home (and a lot of devices soft brick themselves if you cut their connection to the cloud).

the most useful advice i can generally offer is to add a proper network security device running pfSense or OpenWRT to seize some control over internet access and DNS resolution and to implement VLAN segmentation to keep trusted devices secure from trusted* and untrusted devices.