The ones above were posted while I was typing.
No, it isn't, because the 3rd party addons are not from XF nor supported by them. It is like saying you can not fully experience what a new car would be like unless you were first allowed to drive it over to your local Pep Boys, stick every doodad & gadget on it, and then drive it around for a while like that for free.
A webmaster who wants to build a community couldn't care less if add-ons are coded by third-parties or by the XenForo team. I would have never bought XenForo if it wasn't for the add-ons that extends XF with essential features that other forum scripts provide out of the box since years.