1) By default, every word (each character, actually) you input into Spotlight/Siri gets time-stamped and sent to `smoot.apple.com`
2) Even with a Pi-Hole blocking *.apple.com (i.e. using MacOS >> Networking >> DNS Server), on boot all modern Apple Silicon reaches out to security.apple.com (i.e. bypassing the user's manual-input DNS setting), using the DHCP-issued DNS IP [0]
pro-tip: use your router's DHCP to auto-issue your local Pi-Hole's IP address [as DNS] with your IP-leases; then you'll actually be able to block all *.apple.com traffic (using the PiHole which your DHCP issues to, by default)
[0] this is for security chip "lockout" detection (e.g.) and it is pervasive across NICs (i.e. it REALLY seeks any attempt for DNS resolution to security.apple.com)