What makes an arch so strong is its ability to spread and dissipate the force outward and downwards. When stones are placed in the right positions, they push against each other and stay in their own places which made arches structurally sound and highly durable. In building an arch, it isn't stable until the two converging parts meet in the middle, so scaffolding is used to support the arch while it is still in construction. When load is applied to an arch, the stones push against each other and distribute the force downwards and towards the abutment which supports the arch. Arches are able to handle a huge load and allow boats to pass under them which made them revolutionary at their time, being so strong and stable at the same time.
So it's not a surprise that it stayed together when I yeeted a car at it.