Anybody who believes ~30% of the workforce was functionally unemployed in 1999 does not know what those words mean, or was not an adult in 1999. I get what they are trying to convey, but the stronger message is the more straightforward: there are too many jobs that do not pay enough to live on.
For me the true problem which most countries dont even acknowledge is low wealth and capital gains tax. Salaries are not enough because of land prices and the prices inflation it causes through out the economy. You bring down price of home land rent then price of everything else comes down. And their is a lot more economic activity as trillions of dollars are not parked in real estate for wealth generation.
The same fear will happen if you just target investors owning multiple real estate with this tax, or simply forbid by law from owning several flats in high demand areas. The right wing would scream that the hard working French guy won't be able to invest his hard won money, but the very rich foreigners from Saudi Arabia or investments funds from USA will find a loophole thanks to their infinite money and buy all the french real estate.
Hell, most people in my country are against inheritance tax despite a huge part of them not rich enough to pay it, meanwhile inequalities are rising because of inherited wealth. So taxing the land won't happen, the bourgeoisie has been too effective in its propaganda.