So I’m kind of scared about the future of LXC and Incus. Do you have any more information about that?

Canonical decided to take LXD away from the Linux Containers initiative and "close it" by changing the license. Meanwhile most of the original team at Canonical that made both LXC and LXD into a real thing quit Canonical and are not working on Incus or somehow indirectly "on" the Linux Containers initiative.

no one else participating apart from Canonical devs.

Yes, because everyone is pushing code into Incus and the team at Canonical is now very, very small and missing the key people.

The future is bright and there's money to make things happen from multiple sources. When it comes to the move from LXD to Incus I specifically asked stgraber about what’s going to happen in the future to the current Debian LXD users and this was his answer:

We’ve been working pretty closely to Debian on this. I expect we’ll keep allowing Debian users of LXD 5.0.2 to interact with the image server either until trixie is released with Incus available OR a backport of Incus is made available in bookworm-backports, whichever happens first.

As you can see, even the LTS LXD version present on Debian 12 will work for a long time. Eventually everyone will move to Incus in Debian 13 and LXD will be history.

Update: here's an important part of the Incus release announcement:

The goal of Incus is to provide a fully community led alternative to Canonical’s LXD as well as providing an opportunity to correct some mistakes that were made during LXD’s development which couldn’t be corrected without breaking backward compatibility.

In addition to Aleksa, the initial set of maintainers for Incus will include Christian Brauner, Serge Hallyn, Stéphane Graber and Tycho Andersen, effectively including the entire team that once created LXD.