I'm an atheist so got married in a register office. I didn't want a ceremony that was important to me to be overlaid with lots of religious mumbo-jumbo I didn't believe in. That was before the legal changes came in which meant you could have legal wedding ceremonies in hotels etc - we might well have done that instead if it had been an option at the time.
However, there are plenty of people who vaguely believe in some kind of god, even if they don't normally attend church, and if they want to get married in church, according to the laws of the country - with the Church of England as an established church - then they are entitled to do that.
Interestingly, huge numbers of people in Japan opt for a 'Christian' wedding ceremony even though only a tiny proportion of the population is actually Christian, just because they like the 'romantic' image of the church, white dresses etc. So to supply that demand, lots of hotels have built 'chapels' which are not consecrated and are only ever used for weddings. The ministers/priests who officiate at the ceremonies are quite often moonlighting English teachers who have no religious qualifications at all - just because having a foreigner to conduct the ceremony is seen as more authentic.
Meanwhile, there is also a growing trend (possibly anime inspired?) for foreign couples to go and get married at Japanese shinto shrines. I'm guessing they don't believe in shintoism either, they just like the image. Each to their own. At least it is a matter of personal choice.
Apparently I would not be able to get married at all in some countries (Israel, Lebanon, much of the middle East) because I am atheist, and they have no provision for civil marriage.