I have some great ideas: improve education, reduce inequality, introduce preferential voting.
Seriously though, these problems are occuring the world over. I’m not an anthropologist but IMO the root cause is income inequality. Basically the working class are increasingly dissatisfied and the frustration manifests in very strange ways. There’s no fix for this other than societal collapse as a result of economic, environmental, or societal unrest. This part of the cycle will probably take 300 years or so, depending on the whole climate change thing.
The “when transporting a large number of people” is quite a caveat. Sure ok high saturation of public transport / walkable cities is probably achievable with high population density, but in rural / regional areas it’s just not possible.