All in all, most problems with Flatpak are problems, that can be solved
No, flatpak and similar things are designed to bypass the relation of trust between end users and Linux distributions.
Users are required to either blindly rely the upstream authors with the sandboxing, privacy, legal compliance and general quality or do extensive vetting and configuration by themselves.
Additionally the approach of throwing every dependency in one big blob removes the ability to receive fast, targeted security updates for critical libraries (e.g. OpenSSL). And there is no practical way to receive notifications for vulnerabilities and to act on them for the average user.
Traditional Linux distributions carefully backport security fixes to previous releases, allowing users to fix vulnerabilities without being force to upgrade their software to newer releases.
New releases might contain unwanted features or be too heavy for older hardware, or break backward compatibility.
With Flatpak, even if the upstream developer forever releases new packages every time a vulnerability is found in the entire blob, end users are forced to choose between keeping the vulnerable version or update it. Plus, the authors might simply abandon the project.
Furthermore, Flatpak, Snap etc and similarly Docker do not require 3rd party / peer review of the software. Given the size of the blobs it would very impractical to review their contents even if it was required.
No, flatpak and similar things are designed to bypass the relation of trust between end users and Linux distributions. Users are required to either blindly rely the upstream authors with the sandboxing, privacy, legal compliance and general quality or do extensive vetting and configuration by themselves.
Additionally the approach of throwing every dependency in one big blob removes the ability to receive fast, targeted security updates for critical libraries (e.g. OpenSSL). And there is no practical way to receive notifications for vulnerabilities and to act on them for the average user.
Traditional Linux distributions carefully backport security fixes to previous releases, allowing users to fix vulnerabilities without being force to upgrade their software to newer releases. New releases might contain unwanted features or be too heavy for older hardware, or break backward compatibility.
With Flatpak, even if the upstream developer forever releases new packages every time a vulnerability is found in the entire blob, end users are forced to choose between keeping the vulnerable version or update it. Plus, the authors might simply abandon the project.
Furthermore, Flatpak, Snap etc and similarly Docker do not require 3rd party / peer review of the software. Given the size of the blobs it would very impractical to review their contents even if it was required.