Hell no. It's nowhere near 50/50. In my experience the great moments are far more frequent than the one where you want to defenestrate them.

The relationship with them is however massively unequal, in that you basically owe all the support and they owe you next to nothing (at least at the start).

And unlike with partners and friends, you are supposed to have and maintain authority over them, and foster their growth, often against their whishes.

So it's a lot of work. But I for instance don't understand why people get dogs.

When I said sometimes, did not necessarily mean %50 but agreed if negative feelings are close to majority in such a situation then there is some self reflecting to be made.