How does having a child affect a relationship?

My recent posts drew hundreds of comments saying "it's easy for you, you don't have kids yet". So I'm asking the people who already do.

“How does having a child affect a relationship?”

That’s the question I want to ask you today. I don’t feel I have the moral right to speak on this topic myself, so I want to hear from those who already have children.

I decided to ask because my recent posts drew hundreds of comments saying that Nastya and I can build a normal relationship only while we don’t have kids.

That clashes somewhat with what I observe in real life. In my circle there are 4 couples who built their relationship well before children came along, and after the maternity ward they went on building their family just as harmoniously, only now with kids.

In one family, the woman was so bored at home while she was pregnant that she even started a furniture business. Today it’s a great store, Soloha, where Nastya and I have been shopping for about 5 years.

There are also dozens of couples in my circle who had a difficult relationship before children, and after the birth everything stayed just as bad, if not worse.

Reading the comments about how Nastya and I only find time for each other because we don’t have kids, I got curious.

So for many people, having a child rules out the possibility of giving time to the husband or wife they love?

Then again, in my circle I see 4 families with children where the husband and wife are the most loved and closest people on the planet to each other, and they find the time to go on dates and be alone together.

Of course there are far more families with constant conflicts and problems — but those problems existed before the children too.

How do you see this? How did having children affect your relationship with the person you love? Does a child make a happy family of 2 people less happy?