Paris isn't a mass of tall towers. It looks like this:
Building out the housing stock is about building lots more 4-5 story neighborhoods with more densely-packed living spaces, not building skyscrapers kept unoccupied by Chinese millionaires. You can't build enough of those to house the population anyway. The densest town in MA is Somerville, and it accomplishes that without any towers.
Paris is mostly 3-7 stories, but it's a vast amount of 3-7 stories, done in an attractive aesthetic style.
Also, the housing need isn't in "central Boston". It's in Somerville, Cambridge, Dorchester, Quincy, Newton, etc. - places accessible by the T but affordable. A modern urban center doesn't house everyone in downtown. Paris houses no one at all in La Defense.
Nothing. I'm not arguing against this project or projects like it. I think they make the city look nicer. I'm arguing that they aren't a measure of "how we're doing" vs. any other city.