Generally speaking, you’re not wrong. But I’d say it also depends on the use case and your threat environment. If it’s not publicly exposed, I’m generally OK with running an older version of software. In the case of chat software, for instance, it would have to be available only on local network or a private VPN like Tailscale. That can limit its usefulness though.

Revert to an older version?

Your good if:

• It’s self-hosted and open source
• It’s self-hosted and closed source, but doesn’t require online check in ( the DAW Reaper, for example)

It’s a toss up if:

• It’s self-hosted and closed source, and requires online check in.
• It’s self-hosted and closed source, and requires a constant internet connection
• It’s cloud, but open source. (you can generally self-host in this instance)

And you’re screwed if:

• It’s cloud and closed source.

Self hosted in this instance means anything that installs and runs completely locally or on your own personal servers. If someone else’s servers are required I would count it as cloud. Phone apps generally count as “cloud” in this instance.