F-Droid is an installable catalogue of FOSS (Free and Open Source Software) applications for the Android platform. The client makes it easy to browse, install, and keep track of updates on your device.
Running outdated versions of software, whether on your phone or the desktop, will generally expose you to more vulnerabilities and is not best practice from a security perspective.
Does it have an update all button? That’s what prevented me to keep using it some months ago.
It does now yes.
Why would you ever want to do that? Sometimes the older version is better for about a third of the apps on my device.
Running outdated versions of software, whether on your phone or the desktop, will generally expose you to more vulnerabilities and is not best practice from a security perspective.