Nope, you're not missing anything really, but I'm sure glad that not every website looks like a Bootstrap 3.
I think these government ones are more about keeping a consistent style and look across departmental websites, than advertising a product for general use.
In fact, I think the government would not take very kindly to hobbyists making official-looking websites serving a non-government agenda.
Front-end isn't that difficult for websites that primarily display information and at most require a contact us form or some basic CRUD.
So, naturally, given what may be an unconscious existential dread that one day the world may realise that front-end is more or less solved, front-end developers like to make sure that there's always something new to do, rather than admit that a problem is more or less solved.
And thus fashion is born.
Clothing was also a problem solved. We figured out that we needed shoes, trousers, shirts, jumpers when it's cold, coats when it's raining, etc.
But once you have those, well, the tailor has no income. So the idea emerges that we need to have nice shoes, shirts and trousers for special occasions.
And that perhaps some clothing items are better than other clothing items.
And what if you don't want to dress in white and grey tomorrow, perhaps you'd like to be eye-catching?
And so, fashion was born.
The basic template is the same. You have some fabric that covers your legs, genitals, torso, arms etc. and the lower half is, more often than not, a different garment to the top half, to allow for easy swapping of components for different looks etc. But the base structure is the same.
And if you are so inclined, you can have a totally bespoke and crazy item of clothing made for you by a designer.
Sound familiar?