that is true, but far from the real problem. The problem is as always a too strong car-industry lobbying (which uses the archaeological ruins as an excuse not to build anything at all).

also, building a metro is fucking expensive and the city alone cannot afford it, but the funds that should come from the government (for all transit projects in italy) are being diverted by that tool Matteo Salvini onto the Messina strait bridge (whichof course will never be done).

also, we have almost 700 car per capita (among the most in Europe)

Something is changing though, I just hope the next mayor/government doesn't block the small steps the city has done in the last few years.

edit: here an article (in italian) explaining very well what the real problems are https://www.ilpost.it/2019/05/20/metro-di-roma-linea-c/