The EU member states have their own foreign policy and extensive veto rights within the federation. It is not so strange that the EU itself has been slow, if anything I think we have pulled together better than expected.
Individual member countries range from having done a lot fairly quickly to active sabotage. We have member countries like Hungary and Slovakia, who are firmly aligned with the Russian side, as if 1956 and 1968 and the entire iron-curtaint-thing never happened.
Fico in Slovakia is a hopefully crumbling anomaly- the previous governement (while a bit unstable) donated a lot of material, including a criticalzly needed S-300 battery and Mig-29 jets. And even with all the Ficos rambling, Slovakia is making good money selling artillery (both SPGs and ammo) to Ukraine.
Austria donated what amounts to a couple of helmets but no one is talking about that. Must be nice being surrounded by NATO countries and a wealthy world police state across the world you can free-ride.
But the rollout was slow, they seemed reluctant, some countries didn't want to be involved at all, and they waited for the US for a long time...