It turns out my issue mainly caused by my limited understanding of Artifact repos and the dependency chain of the project. Apparently it Artifact repos do caching of all the upstream repos so that's why there where 100k files in there. In the end there were only two company specific dependencies that needed moving.
I accomplished the migration following way (applicable for to all Maven migrations):
Clone the highest dependencies in the chain. (probably contains a name with commons or parent)
Add Azure Artifacts configuration to ${USER_HOME}/.m2/settings.xml and pom.xml as described here: https://robeco.visualstudio.com/Delivery%20Integration%20Services/_packaging?_a=connect&feed=Maven-feed
Retrieve dependencies from current repo
mvn install
mvn package
Create a release version (without -SNAPSHOT behind it) and push it to Azure Artifacts (else you'll get a Can't release project due to non released dependencies error)
mvn release:clean
mvn release:prepare
mvn release:perform
Now you have something like a robeco-common-version1.0.16 build. Now deploy it to Azure Artifacts
mvn deploy
You should see something like Uploading to Maven-feed: https://robeco.pkgs.visualstudio.com/....
Do the same steps for all subsequent company specific dependencies.
Hi friend, thanks for your sharing and please mark your reply as answer and that will help other community members to search this useful information more easily, it just a reminder :)