several things, the Yellow vests want pension reforms that macron promised years ago. The movement was initially motivated by rising fuel prices and a high cost of living; it claims that a disproportionate burden of the government's tax reforms were falling on the working and middle classes
then theirs the Le Pen anti Eu Frexiters
and the anti vaxxers and anti lockdowners
The generals and the people are pissed off about Moslem mass immigration and the way its turned parts of some towns, including Paris, into moslem no go areas.
See, theres a principle when you are in government, only piss off one set of people at a time. Macron has managed to create enough reasons to piss off most of the french population en masse.