I'm generally in favour of a <2% land tax because it is basically confiscatory - over the course of a lifetime (~20 years not owning land, 50 years owning land, 100% tax). That forces people to store their wealth in deprecating assets and means over time the economy orients towards competent asset managers having all the wealth as opposed to the usual equilibrium of forming a landed aristocracy. It also can't be escaped because the land can't be destroyed, not created or moved.
So I don't know much about the French situation being more than a continent away, but in principle a 2% wealth tax can't fix a budget hole. It is also confiscatory, making it ultimately a tool of social engineering rather than revenue raising. It is a policy to eliminate large pools of assets. Things that get eliminated can't be taxed sustainably.