Have a look at https://de.wikipedia.org/wiki/Spezial:Version#mw-version-ext. Notice that the "Version" field for many extensions shows a dash (–), followed by a commit ID and a timestamp. More and more extensions do this, especially the most recent, actively developed ones.
The version number does not serve much of a purpose any more since we switched to [weekly deployments](https://wikitech.wikimedia.org/wiki/Deployments) and branches that can essentially be cut any time, without the developers consciously tagging a version-numbered release. The only place where the version number still appears is on Special:Version, and possibly [mediawiki.org](https://www.mediawiki.org/wiki/Extension:FileImporter) (or not, as you can see). That's basically it. It does not mean anything any more. Instead, the relevant information is now the commit ID and timestamp, describing where the branch was cut, and when.
A version number can still be meaningful, but only if it is actively used as a tool for communication. For example, it would have been possible to announce the big rewrite of the #two-column-edit-conflict-merge interface as a "version 2", and mark it as that on Special:Version. But I doubt we are using version numbers like this. Currently, we show "version 1.0.0" basically "forever". This is meaningless. Furthermore, for pretty much all extensions we develop I would not even know when to increase their version number. What do we count as a major release? What do we count as a new feature that needs an +0.1 increase? Which of the uncountable bugfix patches we do would need to increase the number by +0.0.1?
Proposal: Remove all version numbers from all extensions we develop(ed).
Current status as seen on https://de.wikipedia.org/wiki/Spezial:Version?uselang=en:
* #advanced-search 0.1.0
* #cognate 1.0.0
* #electron-pdfs 1.0.0
* #mediawiki-extensions-interwikisorting 1.0.0
* #move-files-to-commons 1.0.0 (two times for both the exporter and importer)
* #revision-slider 1.0.0
* #two-column-edit-conflict-merge 1.0.0
Related: The author field of some WMDE extension does //not// mention Wikimedia Deutschland, nor the #tcb-team.