I'm not sure what your point is. Do you think the small population on the island should have to pay for all of it?
The French-side Collectivité is technically an EU territory, although not part of Schengen. The Dutch side, as a separate country, is not part of the EU, although it is a constituent part of the Kingdom of the Netherlands. The Recovery Trust Fund, which sponsored the clean-up on the Dutch side of the island, was significantly funded (€4.70M) by the Dutch government, so not dissimilar.
The funding by the EU is a fairly common practice under EU disaster-relief programs. Thus the €4.28M from the EU, €828K from (I assume French) State credits and €444K from the French Collectivité itself is not unusual. I'm just glad it is finally getting done.
Something isn't right about that story. We went by where the boat was that was lodged in the frame of the house. It wasn't there in April"22" when we were out on our Rhino Safari riders afternoon cruise around the island! This is the photo I took in 2018!