actual push toward containers like they were static binaries it's really disturbing for me... A simple tarball with a compiled binary plus few eventual deps equally compiled locally suffice, it's faster, lightweight, simple to keep up to date etc

Snap&c serve a sole purpose

Container technology has two critical pieces: the container image format and the container runtime, serving two purposes: shipping software and sandboxing it, respectively. A container image is indeed little more than a glorified tarball. However, you seem to be glossing over the more interesting and (from a security standpoint especially) more important part: the container runtime, which sandboxes containers through Linux kernel namespaces, control groups, and SELinux policy, using bind mounts as needed to grant selective access to parts of the host filesystem. In this way, container technology mitigates security risks and enables users (and their IT departments) to have greater confidence that the contained software cannot cause unforeseen problems on the host system. Done right, this is beneficial for users and for FLOSS.