No, Debian is typically quite a bit older than even the Ubuntu LTS. E.g. they currently still don't ship a Nvidia driver that supports the 50 series GPUs.

Slower on updates, not slow to run. Slower on updates is referring to how it takes longer for new features / software to be shipped out for you to download. Debian usually prioritizes machines that chug along for a long time without anything breaking, rather than adding new stuff

You're right that it's not slow to run. It is small and fast

Performance differences between distros tend to be negligible. Unless you have a specific use case and a distro specifically tuned for that, you will hardly notice any difference.

Ubuntu is based off the testing version of Debian, so they have newer software versions

Your logic seems sound, yup.

Though broader than the issue you're responding to, the bigger quality of note in Ubuntu, is not that it's slow (nor larger), but instead, the most issue of ubuntu, is that they're very very silly. More marketing silly than sensible development.

Better Ubuntu be slow than fast anyway. See what they do when they try go fast? Like replacing the userland with rust...

That's beyond just "ready or not, here it comes" release model madness.

It's silly.