Diesel or petrol cars

Govt of most of the country is trying hard to ban diesel cars. But why?

I know the part that diesel make lot more pollution than petrol but diesel cars are very reliable and it can be used more than 20 years.

Even because of emition standard car manufacturers are moving to 3 cylinder engine which not reliable than the 4 cylinder one which were standard engine few years back.

So this eco-friendly move don't take in account of the fact that these cars are reliable and dont need to change for years of uses?

Anyway I drive a 1.6L Diesel car which I will not going change 😂😂😂.