I believe Flatpak does.
Flatpak does not authenticate files that it downloads. Please stop spreading misinformation that flatpak is secure. It's not.
If the flatpak (flathub?) repo was compromised and started serving malicious packages, the client would happily download & install them because it doesn't have any cryptographic authenticity checks.
APT and dpkg don’t do that
Apt does verify the authenticity of everything it downloads (by default) using PGP signatures on SHA256SUMS manifest files. This provides cryptographic authenticity of everything it downloads. Flatpak doesn't do this.
Again, this is clearly documented here https://wiki.debian.org/SecureApt