As someone who worked in the very same municipality... one word; bureaucracy.
More specific reasons were. Legal boundaries between ownership and taxpayer money separation. Of cause GDPR is also a big obstacle in joining forces on this scale.
I worked on a project which tried to make a joined venture between several municipalities. I'm not sure if that partnership has ended yet, but overall you could only progress if there were people on both sides collaborating with a "better ask forgiveness, than permission" mindset. As soon as the municipality lawyers or their security officers got involved, all progress stopped immediately.
More specific reasons were. Legal boundaries between ownership and taxpayer money separation. Of cause GDPR is also a big obstacle in joining forces on this scale.
I worked on a project which tried to make a joined venture between several municipalities. I'm not sure if that partnership has ended yet, but overall you could only progress if there were people on both sides collaborating with a "better ask forgiveness, than permission" mindset. As soon as the municipality lawyers or their security officers got involved, all progress stopped immediately.