tbf, the Roman engineering marvels that have survived are largely the prestigious “Some rich elite is funding this and gods help you if you make the rich elite look bad”, or “The military needs this and someone is going to get FLOGGED if it isn’t up to snuff”.

There are a lot of accounts of private construction - particularly of apartments, and especially of apartments in the city of Rome before the establishment of building codes during the early Empire - wherein they were shoddy buildings that collapsed at the slightest (or no) pressure.