It differs from country to country. Some have different primary source of power. Like some european countries are almost fully renewable. Some other countries are getting there.

Depends on the political willpower of the government as economies (thus incentives) lean differently.
These countries can have very green hydrogen if produced using electrolysis. We can go that way too and reduce on dependence on coal (and its price fluctuations). But we have an oil and gas industry to support so.....

I am saying it depends on country.

In those countries that I listed earlier, it is solar/wind/whatever renewable -> hydrogen -> electricity

Fossil fuels are popular because
a) It is super dense source of energy when you measure in terms of J/kg
b) We have literally built our world infrastructure around it. In fact entire cities have been built around its activities whether its mining or processing
c) It is very very mature. The processes around it are more than 90% mature. Refineries, petrol pumps and even engines have barely changed since world war II
d) There is a lot of MONEY and hence political will fuelled by it. Imagine if an entire city like Miri or Port Dickson or Pengerang goes bust because nobody buying the output.

Even if you are having a large fossil fuel plant to produce power to make hydrogen, it is actually more efficient because mass produced power is more efficient than that in your engine. The engine in your car (though I love the sound and feel of it) sucks as a energy converter. Most of them are less than 50% efficient in energy conversion. The typical electric motor can easily do 80% and above. And it can do it across a wider operational range meaning most of the time.